In most cases, no. Any behavior that leads to banning is, without fail, very serious. Additionally, except for spammers and obvious trolls, in almost all cases, the banned member has been warned that their behavior may lead to banning if it doesn’t stop. If the behavior continues (or happens again at a later date), that is a choice the member has made, fully aware of the possible outcome.
That said, we have reinstated at least one banned member in the time I’ve been managing the site. The banned member approached me after several years had gone by and explained that he had matured (he was rather young when we banned him) and gotten a mental illness treated during that time. We allowed him to come back, with the understanding that if he slipped into old habits he’d be banned without warning.
It has come to my attention that a recently banned individual has been lying to several people about the reason for the ban. This is not all that uncommon, unfortunately. Sometimes people say they quit, or make up some story to explain why their banning wasn’t their fault. It’s sort of understandable…I’m sure it’s embarrassing for people to admit what they’ve actually done that got them banned. But I encourage everyone to take such stories with a grain of salt.