There actually is something wrong with Sarge's eye(s).
- In the interest of taking a running gag far, far too seriously... In the episode with the secret service, Sarge claims his eyepatch is the result of an on-the-job accident. However, the eyepatch is constantly (and purposely; it's not a continuity error) switching eyes between shots. In the bodyswitching episode, he tells Dan that he keeps one eye covered because of 'redundancy' - never have two of something when one can do the job. Theory: Sarge received a head injury that rendered his eyes unable to work together. One has to be covered for him to see properly (which is also why he bothers to cover his eye with his hand when Michael briefly, er... jump-cuts the patch onto his own face in the bodyswitching episode). Being the total badass that he is, Sarge just put an eyepatch on and continued killing dudes. The patch just adds to the scariness.
The final scene was Michael's imagination.
Dan and Michael teleport from a field to a hot-air balloon hovering over the same field for no readily apparent reason, Dan confirms Michael's insane theories about the East Coast and is way too nonchalant about Michael trying to kill a kid by spitting on him, and of course the obvious.
It just doesn't mesh with anything that came before it.
Mandy DOES like Dan.
But she has some kind of emotional abuse fetish (or, perhaps a little more sympathetically, she has a thing for Woobies and is kind of playing off that). She goes out of her way to hurt him, and despite sleeping with Sarge (which she goes to great lengths to make sure Dan knows) still shows blatant interest in Michael in front of both Dan and Sarge. Everything she does, just about, hurts Dan in some way. However, she was interested enough in him to date him and was going to sleep with him.
There is an order of Sarges
He says "Hi, I'm the new Sarge", implying that there's more than one. Also he seems to have powers and, like the Chief, to be older than he looks.