“Like me, the guy used to be pre-trib.”
From what I’ve heard, including your story, it appears that most people, as they mature more in their faith, go FROM pre-trib rather than TO pre-trib, fortunately.
Imagine going back to your high-school of 15 years ago and seeing your old teacher and sitting in on a class that you took from him 15 years ago. Now imagine that half of that class he is teaching today is the same students you took the class with 15 years ago!
I had that experience when I visited my old (very large) Assembly of God church a few months ago. My old class was, again, going over revelation and the same people were making the same observations they were 15 years ago as everyone nodded in agreement about the same pre-programmed beliefs. Meanwhile, I’ve been studying it off and on since then and was embarrassed as a Christian as I listened to easily dissprovable comments being made and the teacher nodding in agreement. It was, frankly, weird. Kind of like that part of Pleasantville where the teacher points out to class that Main street just comes back around.
I am noticing similar things in my sunday school class at my current church, only I am not shutting up. The evidence is all right there in the bible for anyone who will throw out their preconceived paradigm and read what it actually says - and in context. I will not let them have a pass.