Luckily he's not appealing a ban that is in any way related to those incidents so whether or not it's true doesn't really matter.
There's literally 0 reason to keep him banned if no evidence surfaces of him breaking any rules on Panda servers. And so far, no such evidence has arisen. And even if you point to whatever wrongdoings he did elsewhere: people who break rules on Panda servers are given another chance all the time; so even if you consider unbanning this one 'another chance' (and why the fuck would you even consider it that), it'd still be within acceptable parameters.
Just out of interest if the console banned him for being apart that group, and the actions he listed are in fact held against surely that is reason enough to hold the ban? I do believe he may deserve a chance but he was banned for being apart of a group with a reputation for doing exactly what he was defending himself for previously?