Considering all of Bashir's high-minded talk about how the ends don't justify the means and how 31 needs to be destroyed, his actions are pretty objectionable.
He blatantly lies to Starfleet Command, he's indirectly responsible for Sloan's death, and then he forces his way into Sloan's mind - a situation we've seen compared to rape in numerous other episodes.
It's not even that so much that bothers me. It's that he doesn't seem to understand what he has done. This was basically his "In the Pale Moonlight." But does he have regrets? No. He plays darts and drinks with O'Brien while patting himself on the back for his ingenuity.
Pretty disturbing if you ask me.