Upon further testing, I'm getting some really weird behavior.
There are actually two banters involved in what I'm experiencing. There's the Minsc/Lilalcor/Keldorn one, and then there's the standard unmodded banter between Minsc and Keldorn when Keldorn is deeply hurt, the one where Minsc starts by telling Keldorn that he'd be much honored in Ramashen.
In my game, I keep getting the M/K/L banter, which is immediately aborted after the first line, then followed by the standard M/K banter.
I surmised that possibly the standard banter was interrupting the banter involving Larry. So I gave Larry to another party member. Guess what? The banter involving Larry -still- starts. So I actually tried -dropping- Larry on the ground a distance from the fight where I'm getting Keldorn sufficiently hurt, and the banter involving Larry STILL starts. It starts even when Larry's not in any party member's inventory. And for the record, yes, it aborts even when Minsc has equipped Larry recently, so that's not the issue.
[More testing]
Okay. I'm totally confused now. I tried healing Keldorn to full, and then CTRL-I'd a bunch of times. And the Larry banter still starts, and still gets aborted. This is even if I drop Larry. I guess that kills my previous notion that Keldorn had to be hurt for that banter to start, but that's the only way I've been able to trigger it without Ctrl-I. If he is hurt, then it -always- starts (and gets aborted) immediately following the battle where he is hurt.
[More testing]
Okay, I'm -really- weirded out now. I actually dropped Larry and then walked into a totally new area, and then I Ctrl-I'd a bunch of times. And guess what? I got the -entire- banter, despite the fact that Larry was lying on the ground in a totally different area! Freaky, heh. If you're curious, the first zone where I was getting the banter aborted was the Gauth/Beholder cave during the Cult of the Eyeless quest, and the zone where it began working (sans Larry) was in the section of the sewers that you get to after going up the stairs on the south end of the beholder cave, where you come out just behind a secret door that you'd previously been unable to open.
Oh well, at least I got to see the full banter now. Just thought I'd let you know bout all this weird behavior though
Qwinn