was i the only one whose favorite scene was the fire extinguisher?

It is a very convincing head-smashing scene. The sound effects and angle of shot seem to be realistic. However it's a movie not reality. If you had seen such a scene in real life and didn't feel disturbed by it, some people would think you're a psychopath and others would think you had no fear of death. However the main point is, people in civil society in times of peace recoil with fear when witnessing such violence first-hand, because the human being is a social animal that usually empathizes with others. We all have heads we don't want to lose. But it's OK to not find this scene disturbing. Even the most vivid art is best viewed abstractly.

The problem is, in your case none of this applies. You are taking a 'justice' view of the situation. Your view is a bit uncritical because it implies that if someone causes someone else minor physical injury and major emotional upset by raping them, then it's 'just and fair' to give him the ultimate sanction of permanent physical injury and/or death in retaliation. This seems disproportionate because it's not 'an eye for an eye', it's 'an eye, a nose and a tongue for a split lip'. If you impose this violent death penalty it puts rape on an equivalent level to murder, which is obviously wrong. If you did this, it would be an incentive for every rapist to kill their victim. After all, it wouldn't add anything to the penalty.

Also, not to mention the fact that the wrong guy was identified and beaten to death with the fire extinguisher. Tenia was in the background, watching. And another guy was masturbating. Mob/vigilante 'justice' makes mistakes. We have laws and courts for a good reason.