Clever blokes, but they really need to learn that you do not need 17 pages to explain the end result. In addition, it would have been nice if they had not only demonstrated the problem, but showed the software engineers how to write proper code so Replay wouldn't kick in all the time. You can't have everything :-).
It just goes to show that you should not add speculative kludges to systems where everything depends on timely scheduling and execution. Unfortunately, I've got a nasty feeling that predicting execution time exactly is an NP-hard problem, so you have to make do with kludges to get anything going. However, they could have been made a bit more intelligent than Replay.