What's up you crazy bastards?

I've only played a few locations, and my home state( I recently moved back) now has blackjack and, well, I've noticed quite a few dealer errors. Far more than anyplace else. Most of the mistakes I've witnessed have been in favor of the player...about 70%. Most between 25 and 100 dollar mistakes. The most insane one was a three hundred dollar double down (six hundred total) that was paid on a loss...A 1200 dollar mistake. It made me think that I may be missing out by not following error-prone dealers around and paying attention.

Does anyone notice/do this at newer casinos?