The whole puddle not reflecting properly is ridiculous. The first thing you would notice wouldn't be the fact that your face looks a little odd, it's that when you move your left hand your reflection's left hand would go up. I know they kinda moved symmetrically when they were looking at the puddle, but you would have a hard time not noticing something like that.
And seriously, why is the bald guy still there? I didn't particularly care about him in the first episode he was in, and I assumed the only reason he stayed on for another was that they wanted to give the Doctor a companion, but didn't want to introduce someone new for the sake of one special. Now I'm just wondering if no one had the heart to tell the actor they didn't want him on the show any more. That being said, always nice to have another male companion.
The concept of sentient oil was pretty cool though, if a little weird. I was actually a bit freaked out because of it, which hasn't happened in a Doctor Who episode in a while, so I hope that keeps up!