SQL reliability requires CLR to fail gracefully in asynchronous exception case, like ThreadAbortException, meaning, CLR should not panic, and it should not leak any resource.
ThreadAbortException can be raised by calling Thread.Abort() on the specific thread.
On the test plan review, one dev asks, “what if two threads call Thread.Abort() on each other?”
I don't know the answer. But it will be interesting to try it out when you have the chance to grab a whidbey beta bits.