Continued: (Was on-site earlier and didn't have time to type the rest as, crazy enough, this was just the beginning of what turned into
years of encounters)
Before I could react to the printer landing at feet (I was frozen) he yelled almost exactly "Don't you ever fucking walk into my office like that again, G T F O" so I slowly stepped out and shut the door. As I said, it (door) was cracked open, and the entire front of the office was a large single pane of uncovered clear glass, so it's not like he was on the phone or I walked in on something.
For certain half the floor heard it, but not a sign of life in the hallway of about 12 other offices. I immediately walked straight to manager/CFO's area and rather calmly (in shock) explained what happened. It was short and sweet as was the experience. He apologized and said to please not worry about it or take it personally, that the person was simply/unfortunately "like that" and best to leave him alone and forget it ever happened, and that he would talk to the CEO about it to have him put in a word.
I'm professional, I had worked Hollywood for long enough to know of his type (first time experiencing anything like that though) so I remained calm and treated this like a test and said "no problem, never happened."
The story made its way around the office and people simultaneously joked about it while saying they were sorry about the experience too, and echoed my manager's advice to leave him alone. Fast forward about a year and one day he was gone. No one talked about it. I'm guessing the company finally got enough on him to terminate without worry of blowback. He was a partner and probably had a decent contract in place.
Now, something like 5 years after that (I had moved on to greener pastures) I was out front of a community volunteer bike shop chatting with the team. They were sticking around after-hours to let a metal salvage person take away some old/rusted inventory. A beat up old van with metal junk piled on the roof parks nearby and who walks out and over to us?? It's the guy, I recognize him instantly and as his eyes meet mine I say with a big smile "firstname-Fuckin-lastname, how the hell are ya!" and this time he is frozen, turns right on a dime, and starts power walking back to the van. I follow saying something like hey hey, come back, no hard feelings, but he must be so embarrassed he runs the rest of the way and jumps in the van and peels off. I heard he never came back to that shop again. He went from partner at a well funded firm to east LA metal salvage work. It was such an amazing feeling. I do feel for him though. As someone pointed out in comments he very likely had a mental or drug related issue. What a wild world.
Signing off.