Yeah, nothing on RTS and HotSpot can, occasionally, get false positives. Now its obvious to all and sundry that Lyon hit it, the on-field umpire should have given it out. No argument there. The standing umpire ****ed up big time. But not being able to see the hotspot occur, in combination with the lack of RTS, means that definitive evidence does not exist for Llong to overturn the on-field decision. It's probably enough for him to make the decision himself. But that's not his job.
Nigel Llong the umpire can infer that it was out, but Nigel Llong the process-following Decision Reviewer cannot.
That said, Jono is 100% right about him being a dick for the "could have been anything" comment, but I imagine he knew he was on-air and didn't have time to explain the intricacies related to the key piece of definitive evidence being off screen because the HotSpot FoV is **** for sweep shots.
As an umpire, everything is about processes. Your processes are what make you get decisions right more often than not. But sometimes, very rarely, they just don't work -- and you have to accept that. But if you've developed them correctly, they're still a damn sight better than any other set of processes, or not having them at all.
Llong has done everything by the book but has been forced to make the wrong decision. It sucks, but these things happen. Unfortunately, this failure of the DRS technology and process had big ramifications for the match. But don't throw the ****ing baby out with the bathwater by suggesting DRS should be scrapped. It corrects the extreme majority of poor decisions (or, at least, has the potential to if Brendon McCullum doesn't gamble them on marginal LBWs in the first hour of every innings).