Once you dig through the censorship issues and publication bans, the actual court order says this:
- It is declared under the Family Law Act that:
(a) AB is exclusively entitled to consent to medical treatment for gender dysphoria and to take any necessary legal proceedings in relation to such medical treatment;
(b) Pursuant to para. 201(2)(b), AB is permitted to bring this application under the Family Law Act and to bring or defend any further or future proceedings concerning his gender identity; and
(c) Attempting to persuade AB to abandon treatment for gender dysphoria; addressing AB by his birth name; referring to AB as a girl or with female pronouns whether to him directly or to third parties; shall be considered to be family violence under s. 38 of the Family Law Act.
Publicly available at
IN THE SUPREME COURT OF BRITISH COLUMBIA
Citation: A.B. v. C.D. and E.F., 2019 BCSC 604 Date: 20190415 Docket: E190334 Registry: Vancouver
C.D. and E.F.
Is CD likely to commit acts of family violence against AB?
 Family violence can take many forms. Family violence is defined in s.1 of the FLA, but that definition is inclusive and not exclusive. The inclusive definition of “family violence” recognizes that the risk of harm extends beyond the infliction of physical violence: Morgadinho at para. 59. I note that in particular, the definition encompasses psychological abuse in the form of harassment or coercion, and unreasonable restrictions or preventions of a family member’s personal autonomy. In the case of a child, both direct and indirect exposure to such harm may constitute family violence.
 This Court has already determined that it is a form of family violence to AB for any of his family members to address him by his birth name, refer to him as a girl or with female pronouns (whether to him directly or to third parties), or to attempt to persuade him to abandon treatment for gender dysphoria. AB says that the evidence establishes that CD has done all of the above, and has continued to do so even after the Court found that these actions were contrary to AB’s best interests and constitute family violence.
 In argument, the focus of AB’s concern was CD’s continued willingness to provide interviews to the media and social media outlets in which he identifies AB as female, uses a female name for AB, discusses AB’s personal and medical information in detail, and expresses his opposition to the therapies AB has chosen.
It goes on. Like in this subsequent court process on the same matter.
So, while we here probably should refrain from using any names to identify the persons involved:
We see clearly that this court decision refers to addressing the transitioning person directly or through third parties in the wrong way constitutes punishable "family violence".
It is therefore not true to just assume that this is solely based on the father's public words. Although that probably adds gravitas and makes it much easier to prove that he continues what he was told not to do, privately and publicly. As the court predicted, the father failed to comply to these orders on multiple occasions.
These proceedings are analysed an evaluated in
— Pat Shannon: "Trusting Transgender Youth: A Commentary on AB v CD and EF", Candaian Bar Association, 2019 (For the original ruling)
And for the latest arrest:
But what began as a family court dispute has now wound up in criminal charges due to allegations that C.D. is persistent in violating court orders.
The orders instruct him to not make public any information that would identify A.B., or the medical professionals involved, to call A.B. by the child’s preferred name and gender pronoun, and to not share his opinions of the case publicly.
The British Columbia Court of Appeal laid out the court orders C.D. was to abide by in January 2020. Since then, the B.C. Prosecution Service alleges he has failed to do so on multiple occasions.
In June 2020, C.D. gave an interview to a YouTube channel, where he’s alleged to have identified health-care providers, revealed information about A.B.’s mental health, medical status or treatments, and gave out information that could reveal C.D., A.B. and the mother’s identity.
He was charged with contempt of court, and that matter will come before the court in April.
On Tuesday, C.D. was back in court, arrested for allegedly breaching court orders again. The B.C. Prosecution Service told National Post that “the subsequent breach of court order allegations are being treated as aggravating circumstances.”
This is somewhat mitigated by issunig the following:
“This order should not restrict C.D.’s right to express his opinion in his private communications with family, close friends and close advisors, provided none of these individuals is part of or connected with the media or any public forum, and provided C.D. obtain assurances from those with whom he shares information or views that they will not share that information with others,” the court said.
—Tyler Dawson "B.C. father arrested, held in jail for repeatedly violating court orders over child's gender transition therapy
He is alleged to have revealed information about his child's mental health, medical status or treatments, and gave information that could reveal the family's identity", National Post, Mar 17, 2021
The complaints raised here in comments and expressed via downvotes seem to require some redundancy and meta-communication. This answer is not evaluating the personal situation and family dynamics of anyone involved in that case. It does not take sides whether anyone is 'right' or 'wrong' in that case. It not even condones whether anything the law says or the court ruled is of any such quality. This answer merely shows what the courts have ruled.
To repeat from the court ruling:
In conclusion, I find that AB is an at-risk family member who is highly vulnerable. I find that his father’s expressions of rejection of AB’s gender identity, both publicly and privately, constitutes family violence against AB. Finally, I find that CD’s conduct in this regard is persistent and unlikely to cease in the absence of a clear order to restrain it.
Under 'scope of the restraining order for protection'
I begin with conduct that has already been declared by this Court after summary trial to be family violence. This includes attempting to persuade AB to abandon treatment for gender dysphoria, addressing AB by his birth name, and referring to AB as a girl or with female pronouns, whether to AB directly or to third parties and publicly.
The protection order is required to be prepared by the Registry. However, I will summarize the substance of the order here:
a) CD shall be restrained from:
i. attempting to persuade AB to abandon treatment for gender dysphoria;
ii. addressing AB by his birth name; and
iii. referring to AB as a girl or with female pronouns whether to AB directly or to third parties;
So, the issue of 'how to refer to his offspring' is clearly one major part of the current arrest. As the court is quoted: "the subsequent breach of court order allegations are being treated as aggravating circumstances."
'It was not 'solely about talking details to the press'/'violating court gag order'.
The accused CD was found to have violated 'how to refer to/address his offspring, both directly' and indirectly. Like for example by contiuing to repeatedly using the birth name, 'the wrong pronoun', and he was found in violation of 'speaking about the whole topic, publicly'.
Just the continued usage of birth name and prohibited pronoun used were considered "family violence", and formed one significant part of the support for the 'protective restraining order' and the arrest warrant that was issued.