Of course I'd be able to add it in if I'm able to reproduce it. Any tips on how to reliably make it happen? And how does it crash? Does it like freeze or completely crash or just ends up working wonky? Even if the button is there on an event, it shouldn't matter really. Though clicking on sail button and some event button at the same spot might do something weird. Might be some timing issue related to looting fast ie. not letting the timers run their course. I'll have to do some investigations...
edit: Now that I thought about it some, I could even do a safety "hide all buttons" when sailing from battle to event just in case even if I can't repro the issue myself. That at least should ensure it stops messing with the next event.