In the United States there are different types of military honors that are rendered at a funeral service and they are governed by section 1491 of title 10, United States Code which mandates that upon request the following be provided for all veterans:
c) Ceremony.--A funeral honors detail shall, at a minimum, perform at
the funeral a ceremony that includes the folding of a United States
flag and presentation of the flag to the veteran's family and the
playing of Taps. Unless a bugler is a member of the detail, the
funeral honors detail shall play a recorded version of Taps using
audio equipment which the detail shall provide if adequate audio
equipment is not otherwise available for use at the funeral.
Where a veteran is defined a former member of the armed services who were discharged under other than dishonorable circumstances, as well as former members of the Commissioned Officer Corps of the Public Health Service or National Oceanic and Atmospheric Administration whose funeral honors are performed by the Coast Guard.
Within the general public there is some confusion as to what military honors actually entails. As per Public Law 106-65 Sec. 578 the minimal standard is defined as the folding of the flag, presentation of the flag to the veterans family, and the playing of Taps; however, each branch is responsible for setting their own standards above and beyond that.
The Army is quite specific about the type of funeral honors and details them in TC 3-21.5 (FM 3-21.5) Chapter 14 where "full" honors are defined as the following:
a. A fullmilitary [sic] funeral honors normally consist of, or is
supported by, a 9-person funeral detail, with the following elements.
· Casualty assistance officer (CAO).
· Officer in charge (OIC) or noncommissioned officer in charge (NCOIC) (appropriate for the rank of the deceased).
· One bugler to play "Taps" (or electronic recording).
· Six active duty pallbearers/firing party (dual function, the pallbearers also serve as the firing party and will render these honors).
· Military clergy (if available and requested).
b. If resources permit, a larger funeral detail may be provided, which is composed of all the elements of the nine-person funeral detail, and may also include ... [etc.]
c. A two-man military funeral honors detail consists of the following elements.
· OIC/NCOIC (appropriate for the rank of the deceased).
· Enlisted Soldier.
· One bugler to play "Taps" (or electronic recording).
However, in AR 600–25 they are also very specific that only Active Duty Soldiers, retirees, and Medal of Honor recipients are eligible for full honors, although in the case of restricted resources, retirees may not be rendered full honors. Veterans are eligible for the service detail as previously discussed. The Navy, Air Force, and Coast Guard follow the standards that are set by the Army.
The fact that the character was a veteran of the Marines raises an interesting difference between the services in the United States though since according to MCO 3040.4 Chapter 6 Section 7:
a. Marine Corps policy and tradition has been to provide the maximum
number of personnel when rendering MFH [Military Funeral Honors] at any burial/inurnment. Marine Corps activities will provide MFH support within the constraints of available resources; however, MFH support consisting of the minimum two persons, as required by Reference (k), must be the exception rather than the norm.
Thus, if the plot summary is correct in indicating that full honors were rendered and the character was a veteran of the Marines then the scene is actually correct given their branch of service. Had the character been a member of any other branch then the scene would have been incorrect.