Happens on mine (still) every once and a while. This is after having the key switch blade feature removed from the key per a service bulleting for my 2010. The first time it happened they said it was do to the battery, which they replaced under warranty
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I have to twist the steering wheel to remove the key when it gets stuck. Seems to be related to when the steering wheel locks after turning the car off. Poor design of GM's part the way the steering wheel lock and key cylinder interface.