Agree with the previous posts, but to put your mind at rest further....

The problem with overfilling is when the oil level is high enough that the crankshft dips into the oil, effectively whipping it up like a blender. It looks frothy, and air bubbles don't lubricate very well. When you pulled out the half quart, it was either golden or dark coloured like oil should be, or it was frothy like a milkshake. If it wasn't frothy (and it is very unlikely that it could be with only a half quart overfill), then there was no possibility of damage.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue