As long as the last recorded price is above the highest current bid, a short sale can be processed. If the current price is $6.04, and the best bid is $6.03 or above, even by $.0001, a short with a limit of$6.03 can execute.
Conversely, if the last recorded price is $6.04, and the best national bid is $6.05, no short sales can be executed until the recorded price exceeds the best bid.
The only thing the 10% drop does is trigger the restrictions for the remainder of that session, and the following session.