I don't get why some of you wouldn't at least ask your employer if it's ok? Of course, if they say no then you're not going to want to argue over a technicality in the policy, but that's the worst thing they can say.
So basically, you stand to lose nothing and possibly come away with a free upgrade. Win-win? (Though obviously say "I will travelling on BA173" not "I deliberately timed my schedule to get on one of the few flights that breach the 8 hour rule"!)