I'm guessing that there actually was no call at this instant, and they ruled out of bounds after the goal was scored?
Was it a call from the head referee, or did he look over to the line judge?
Either way, if the whistle blew before the goal, then obviously it shouldn't be a goal. If the line judge's flag went up before the goal was scored, it shouldn't be a goal.
I'm assuming therefore that no call was made, the goal was scored, and then there was a call of out of bounds.
Maybe it's just that I played/reffed forever, but on first watch of that video in the first Tweet I said that's in. I think it's close, but it's pretty easy to get right--especially with replay.
I think there is clear video evidence. It's the right call. Ball was in play. Goal counts. The only reason the call on the field should hold weight is if it impacted the players on the pitch--and assuming the call wasn't made until after the goal, then it clearly did not.