He broke the glass and the unreinforced cement fascia on the building face, all cosmetic and not structural elements.
Fly a Cessna 150 into a structural member, all you do is scratch up the pillar and destroy the Cessna.
Good point....though he should at the least face time for ignoring the warnings. Even if there's a reasonable explanation, like his radio stopped working, he was fiddling with the dial and looking for a good rap station or he went temporarily deaf, he ought to get 30 days.
I can think of a 100 pound payload that would be explosive enough to do more than mar a pillar. We've been far too lenient with all these jokers in small planes knowingly commit airspace violations.