Mt.Gox wont let the script scam you (unless there is an exploit or something).
With Mt.Gox, you only need to trust them. You don't have to trust the users whom you are buying from (which is pretty much anonymous).
this works both ways then, buyer and seller.
so incase MTGOX does not get hacked in any way and MTGOX does not scam it is 100% safe.