Actually I think you missed my point. Even if they are fully capable of handling both operations at once, NASA policy should be, given the high profile nature of a shuttle mission, that nothing will be attempted concurrently with an emergency landing so as to avoid the perception, and resulting liablilities, that every precaution was not taken. This would occur even if nothing about what actually happened had anything to do with what was going on. Guilt by association is the point.
But putting that aside, what about the real possiblity that someone or something that is going on while testing the strat will screw up (Murphy's law assures this will happen) and send a loose strat floating across the airbase or something else totally unexpected and not anticipated. I know that NASA is way more conservative than that.