As Chrisblack10r said, that bolt isn't designed or meant to hold the wheel back, and nor are the lightech adjusters, so I'd be more than keen to make sure everything else is right ...
At the end of the day, the wheel has moved forward, and it shouldn't be able to move if its correctly torqued up with all spacers, bearings etc etc being present and correct. Even if that bent bolt was left off, the wheel shouldn't move. So the spindle nut either could not have been torqued up correctly, too much is not good either .. or a spacer was / is missing or wasn't seated correctly when the nut was tightened.
Assuming bearings are all good, and the outer spacers are all in place, have you checked the spacer is in place on the inside of the cush drive / rear sprocket carrier, I have known these to drop out in the tyre shop before ...
