Had Sinister not been in the peek of his current anger, he would have taken note of Remy's contrite and apologetic attitude. He would have immediately used it to his advantage. Two things he would notice in the future, perhaps an hour later after sitting down and fully reviewing the encounter.
But as it was, Remy peeking in and mumbling something only set him further on edge and a large metal pipe ripped away from the wall and threw itself toward the boy and the tesseract. Sinister didn't look back, still stalking his way toward his private chambers. What few other minions were around immediately decided that their business was no longer taking place in his vicinity, even if it should have been.