[Redsoxx15]

Its possible to strip a bolt with an Allen wrench if you use a standard on a metric bolt. Your situation is weird though, the only thing I can think of is if you only had the Allen wrench seated halfway down, because of whatever coating the bolt has. It sounds like you know what you are doing though so maybe its just bad luck...

 

[Redsoxx15]

This may sound dumb, but have you tried taking the left side out with the right side tightened down? Sometimes the tension of taking one side completely off will make the bolts still in harder to get out.