macman, I'll give you 3 good reasons one might have to sell :

 

1.  Margin Call : even if not too extent on margin, drops like that can endanger one's position

2.  Money needed, while one expected to be able to sell a few at $5 at this point, has to sell more

3.  Fear that this will go down more, and maybe combine with 1 and 2

4.  I'm sure there are even more valid reasons

 

As for the generous advice of never buy on margin, ORT is precisely the company that could warrant the exception. "Bet the farm !" Alas, the SP action must keep one very wary of margin