Unless I'm wrong, the body contact makes that a foul. Sometimes it seems like plays don't get called cause they're too awesome, and I'm mostly okay with that.
The point about the Rudy trade is that the Raptors wanted to be rid of him (and from multiple reports had basically offered him to everyone), and the team taking on salary in a dump trade should get something to offset taking on a lousy contract. Ujiri wasn't going to send a first rounder in this year's draft, but you can at least hold out for a second rounder or super-protected first to be conveyed in the future.
I think you're right about ownership wanting to have a good team in place for the new arena, and I think they're in the same boat as the Cavs, Wiz, Pistons, and maybe some other teams that are trying to accelerate their timetable for winning for whatever reasons (impatient owners, fan fatigue), even if they might be better served by being patient and stockpiling assets where they can pick them up. Which is why everyone liked the Williams acquisition. Trading for Rudy isn't the worst thing ever, but I don't think it's a good use for next year's cap space or even the best deal they could have struck to bring him to Sacramento.