k, so my uni (brand spanking new) is ooc. I have a 29 in. KH and the right crank arm was wobbling outward (away from the uni) and I pulled the crankarm after unscrewing the button as far as it would go. now the button is out and the crank is off the spline. Its times like these II wish i had never picked up this sport 
So… Put it back on? It doesn’t sound damaged, just loose enough that you pulling could get it off. Just set the crank back how it was, hit it with something hard a few times, and then re screw in the bolt. I’m not an expert on putting cranks on though, someone else probably has better advice.
If you haven’t had any issues with the bearing moving but issues with the crank; take out the spacer (between the crank and the bearing) stick the crank back on, pound it into place and screw that sucker down. If the crank interface was stretched/damaged then removing the spacer should make it a tight fit again, you only risk slight bearing movement.
Or if you are feeling crafty and don’t want to risk bearing movement (not all that common) make smaller spacers or shave down the existing one. About 3mm less should be lots.