The best way to start an abuse thread, put a large irrelevant image at the top of your post. That aside, it's clearly a decon- I wasn't there for the other offenses, but I'd assume a L4 would be smart enough not to lie about it when the devs can check the logs at will.
Actually, I'd like to see a /denybuild like command that stops someone from building at the beginning (say, two minutes) of a game, for a set period of time (similar to ban.) I'd imagine this would be more punishment for someone who clearly doesn't care about being banned, and it'd help prevent early decons. Another route would be a complete denybuild (still within time constraints, ex "/banbuild player 14d decon,") leaving it to their team to vote to allowbuild them as they see fit. Granted, this could cause problems, as the person at hand is clearly a griefer, but assuming they cause more problems, a 14 day ban might be a little on the short side.
That's just an idea, it could end up being terrible, but just thought I'd throw it out there.
In this case, banning seems to simply delay the inevitable, rather than teaching the offender a lesson.
As for the Official Servers not being newbie friendly, I tend to give a lot of slack to newbies if they're doing something counter-intuitively. However, if it's clear that they're just doing stuff like this for shits and giggles, I'm much more tempted to bring down the hammer.