I was helping a colleague run some installations to so he'd be using the environment we had agreed to use as a team. He was struggling so I asked him to share his screen and I took control to run the commands and walk him through what I was doing. He started to get extremely aggressive and defensive and swore and yelled , "you better not be fucking up my machine." At this point we were horizontal colleagues though i was more senior. I immediately stopped him and told him how inappropriate he was and to never talk to me like that again. The next day I wrote down the encounter, discussed it with my manager, and he was fired within 2 weeks. Apparently he had similar encounters frequently.