"Your door was open!" Granted, everyone's door's open, but that's one of those details Mac doesn't care to incorporate into his calculus. When you're eternally mentally operating in whole numbers only there isn't a lot of room for anything past a decimal.

On the upside, despite the swearing, bleeding and very circumstances of this encounter between a grown man and a young woman in her bedroom at night, nothing about Mac reads as very predatory. Just fucking clueless. He also doesn't look like he could take either of them in a fight, given that they're both in position to throw down and he's still against the wall trying to staunch his nose with his uniform.