I have another candidate explanation, which would certainly be the right one if it were me rather than you: You've got into the habit of going and checking your email (on a "real" computer) when you get up, and you felt the urge to do that because it's a habit. The idea that it might be because the iPad didn't correctly report your email situation was a rationalization rather than the real motivation.

On the other hand, that historical odd feeling of mistrust of new things isn't something I have. So while I'm sure the explanation above would be right if it were me, it probably isn't for you :-).