This refers to the same PCPSR survey published on Dec 13:
Those who say that Hamas did not commit the atrocities seen in the videos are higher in the West Bank (97%) compared to the Gaza Strip (83%), among the religious and the somewhat religious (91% and 92% respectively), compared to the non-religious (75%) and among supporters of Hamas (97%) compared to supporters of Fateh and other forces (85% and 81% respectively). Belief that Hamas fighters have committed atrocities against civilians is also higher among those who did watch videos showing such atrocities (31%) compared to those who did not (3%). In the Gaza Strip, 41% of those who watched the videos believe that Hamas did commit these atrocities while only 8% of those who did not watch these videos believe that Hamas committed atrocities.
I think the middle sentence (with the 10:1 ratio) thus refers [only] to the West Bank. (It was about 5:1 in Gaza.)
Also, this doesn't look like a controlled (cause -> effect) experiment. Those who were more inclined to believe that Hamas committed atrocities might also have been more likely to seek out such videos. There's a para before that covered the Q if they did see videos:
85% say they did not see videos, shown by international news outlets, showing acts committed by Hamas against Israeli civilians, such as the killing of women and children in their homes; only 14% saw these videos. The percentage of those who say they have seen these videos is higher in the Gaza Strip (25%) compared to the West Bank (7%), among the non-religious (31%) compared to the religious (15%), and among supporters of other forces and supporters of Fateh (21% and 20% respectively) compared to supporters of Hamas (12%).
(And of course, some may have seen videos but claimed in the survey response that they didn't. The survey had no way to double check that.)