I think it depends on the situation. If your gut if all torn up, then it may not be worth touching anything that might throw it off or make it worse. However, if you have no apparent probs with an occasional cheat, that might be another story.
The first time I went on lowcarb, I was absolutely diehard obedient for many months. Then finally I broke down and made a big cheat with a bunch of cake. End result was a few hours later, my gut started on a 3 day long purge of confusion. My gut if usually pretty tough and I had no idea that was going to be the outcome! Lesson for me is small cheats once in a while are not a problem but a big cheat after a long while of no cheat is something my gut can't handle.
I think sometimes people attribute reactions to cheating as being more sensitive but I suspect for many, it's simply a matter of your system adapting to what it usually eats and not being prepared for something radically different. Many people experience constipation when they first go on lowcarb but given time, the system adapts and the problem is gone. Some say it's because with high fiber, the gut no longer needs to physically push the food along so it gets lazy and no longer works as hard. But if you suddenly stop the fiber, the gut is left flat footed and takes a while to get back to work moving the food along via those contractions it does (forgot name of them).
I don't know if a bite of wheat now and then is a big deal in the long run for many people. I suspect if we just ate a bite now and then and never over did it for our whole lives, then very few people would have problems. But once the whole immune reaction kicks in, metabolism and insulin response is screwed up, etc, then the margin of safety is a lot smaller and the risk less worth it. But how dangerous is an occasional bite if no problems have yet come up? Hard to say..