I just found a wealth of oddities on a new char try in the warehouse near SGS, where Newton is milling around.
I was ready to level up, and in the process of opening a lock.
I wanted to see in the char window if I had enough skill, (Yes, I know I would just have to wait), then pressed escape.
It asked me if I wanted to abort the level up.
I clicked no and immediately pressed esc again.
Now I'm officially level 4, but I didn't gain anything for it, I got attributes 3, 10, 5, 4, 8, 3, 7, I didn't gain any feat (currently at 4, including PSI Empathy), and my skills didn't change either.
XP is at 2/8, which sounds about right, in contrast to everything else.