The morality of Wikipedia edit
Wikipedians, in general, have a guideline to not bite the newcomers. However, this is not always followed, and often, the people who are subject to bans due to this are not given a second chance nor are they able to explain themselves. Often, this is simply because they did not have time to read all of the hundreds of guidelines that, for some reason, they are expected to before editing. For example, a friend of mine was banned because he thought that someone had blanked a page, when it was simply being moved. He reverted this. He was then banned because of it. Such incidents don't do wonders for the PR of Wikipedia.
A rule that I always follow when doing counter-vandalism work is, if the user hasn't been warned, just use a level 1 warning, and maybe even ask what happened. Then, if they do anything else again, start ramping up. Don't go straight to a final warning unless they caused a very major problem, and it is obvious vandalism. If you do, this could cause a person making good-faith edits to leave or get banned. This discourages newer editors from staying around, as they don't want to be banned for a mistake.
I recognise that vandals are typically accounts that are newly made, but at least check their contributions for good-faith editing to ensure that it wasn't a mistake. We're all human, we aren't perfect, and everyone makes mistakes. I would suggest that some sort of supervision be required for new CVU members (though nobody is probably going to do that) so no incidents like that occur. It would be to everyone's benefit and would likely reduce the number of people banned for mistakes. It would also make sure everyone knows how to do counter-vandalism, as there are many other kinds of mistakes made by newer CVU members.