I'm all for believing in and forgiving Valentin.
Since he promises he won't do it again :)
He's useful – he plays and participates in discussions. Give the guy a chance.
And about the "kindergarten" – we all came from there. A bunch of guys in their 30s and 40s are playing children's games until their wives take the computer away and then they start talking about a "kindergarten"...
Unban the person, until the first warning :)
Although I'm somehow sure that someone will immediately give him a warning for some past post. :(