I can't put my finger on it either. They have a certain number of bodies in the truck(s), chances are they could say how many. I could understand the hesitation if they had pieces of people. Otherwise, it's poor public service on the part of those involved to act conspirational. After all, it's not some kind of national security issue (although these days everything is turned into a national security/Department of Homeland Security issue).
Of course it could be some two-bit public official who's milking his 15 minutes of fame (And yes I've met people that would do so). "Behind me you see two refrigerated trucks with bodies in them. I won't tell you how many, but I will tell you there are bodies". Easy explanation, and I wouldn't put it past some officials at that level, in Florida.
Quite possible.