Mouse-wheel up will zoom the camera back into first-person. There is a bug currently where if you have your tablet in your active hand it won't work, but you can press E to switch to your other hand and it'll be fine again.

That's really strange. Could you try disabling the 'Mouse Wheel Zoom' option on the misc page in settings then starting a new game?

Haha good. Plenty of bugs in the game but that behaviour legitimately surprised me! Have fun!