The point is it wasn't all or nothing. Perhaps the trade would work out (as no doubt they hoped), but it didn't The good news is that the loss was mitigated by getting back that 3rd rounder. But of course it is a net loss. Such a mindset is usually how businessmen approach risk; it's not risk or no risk, but rather how much risk at what price.
And despite what some might think, there WAS value for having Sammy for a year. He helped the Rams to a division championship and a turnaround in team success and expectations. Was that worth a 2nd round draft pick? That's debatable; but it was in my mind.