In the core rule book on page 24 under Opposed Tests it is written that should both parties fail [an opposed test], then one of two things occurs: either the test ends in a stalemate and nothing happens, or both parties re-roll until there is a clear winner .
Now in case of an Opposed Stealth vs Awareness - test, if both sides fail their test, would you rather have them re-roll until there is a clear winner (and the sneaky action is successful or the character is spotted) or would you go for the stalemate option (although, what would be a stalemate in such a situation?)
I know the very next sentence in the book says that it is left to the GM's discretion.
Nevertheless I'm interested in how other GMs handle this in their game.