What most of those tards don't realize is that prisoner exchanges only happen for valuable prisoners. If you have value to the enemy that increases the odds that they'll bid for your release, and if you have value to the captors (information, etc.) that increases the "price" they can charge.
Coach Red Smear has no value to Russia or Ukraine at all, so if the SBU had actually captured him, they'd just execute him over trying to do an exchange.
People going "buuuuuh he's Chilean (American, actually), they can't do that" -- yes they can. He willingly inserted himself into the situation, was not abducted or forced to take a position. He wasn't there at the behest of a government. The local embassy and ambassadors don't have a lot of obligation to get him out. At most they can do is sue for restitution, if they can even figure out how he died. At this point it's easy to chalk it up to the fog of war.