Barry, given the circumstances I am a little paranoid about any odd behavior, but I don't think I would have even noticed the gaping was a problem until this incident. I knew how to take care of my clams, but I didn't even KNOW that gaping was bad until I had this happen to me and read about it on this board!
Also it's important to note that I did NOT treat the tank. Antibiotics at the dosage I was using, would have surely destroyed the biological filtering capacity of the tank and crashed the tank! I added a note about that in my last post so no one will get confused.
I am keeping the clam in a tank now that was never infected with the bacteria/virus. The post-antibiotic-treatment slime I guess was caused by the clam's reaction to the antibiotic. I suppose any irritant, bacteria or otherwise, would cause the clam to slime like that. Another possibility is that the clam, while living in the antibiotic bath, developed immunity toward the root of the problem and the slime was just the clam getting over it (the root cause could very well be viral).
There are just so many possibilities. That is why we really need to have some sort of pathology work done. Only then can we know if the root cause is viral or bacterial and have some sort of idea when the original tank of infection is safe for new clams.