Both are at fault, but the bullies in my eye should be given more punishments than the victim. As someone who has been bullied, and pushed near the point of breaking, I have sympathy for the victim. That’s not the say that he should not have any consequences, however, they will be less than the bullies.
The analogy I’ve been seeing this as is that it’s the snowflakes on a branch. This branch is enduring many snowflakes, staying straight and upright as long as possible. A group of big snowflakes keeps deciding to land on this branch over and over and over again, until the branch snaps. Would you blame the branch for snapping? Would you blame the snowflakes who knew that this branch would eventually snap from the weight? I would blame the snowflakes (the bullies) more than I would blame the branch (the victim).