I didn't much enjoy it when I was at the other end of it though, and sometimes he went too far. "Try to understand why the person doesn't understand" wasn't something he did enough -- sometimes the person doesn't know the right questions to ask, they just know that their thing doesn't work.
As a helper, it's hard to find the right balance, and I think the most important thing is that if you're getting emotional about it, step away and let someone else take the question. (I at least have been getting better at this over time.)
That makes sense if they're just visiting the channel sometimes. But I'm guessing they saw themselves as somewhat responsible for the community and quality of discussion in the channel, and then just walking away isn't really a solution.
I spent over a decade in #perl on freenode/libera and saw so many abusive events that I eventually got tired of hanging out there, mostly due to him but in part also due to a handful of others displaying similar behavior. All the same I was always grateful for how tirelessly he spent so much of his personal time providing help, and I'm sad to learn of his passing.