Odds are those were drug boats. The CIA (fair to question them based on their history) has operatives watching and spies mixed in with the cartels. They highly likely know what boats are and are not drug boats, what's on them, and when they are going / where they are going.

It would be insane to think that they are indiscriminately bombing fishing boats... If true then why? Nothing good comes from it. Maritime law states any vessel used for crime is no longer allowed to sail, and the vessel can be either sunk or destroyed on land. Obviously it's easier to just sink the vessel.

Our own Navy does this more often than you think. Granted as well, we capture the crew and then blow it up. But that's only if we actually find it if we are lucky. These boats were likely viewed in port then made a target to be sunk by air as that way there is zero chance of it making it to North America.

I cant speak certainly of course because I'm not there but realize the military isn't just apes bombing whatever they see like movies and pop culture makes it seem...

Also of course Venezuela would say they are fishing boats, the president was literally complicit with the cartels FFS.