I think conscious decisions might be overstating it.
The tackle happens, and he moved to blow the whistle. Haaland unexpectedly gets up, and he changes his mind, motioning for play to move on. This happens in about 1.5 seconds. Haaland plays the ball, and he changes his mind and has decided to blow before the ball gets across the half way line. That last bit happens in less than half a second.
I suspect he's seen Jack with three players around him, and has made the mistake of thinking it's just not going to reach him, so blows up. By the time he whistles, something like a quarter of a second after beginning the motion that he's going to, the ball is with Jack.
Imagine if any of us had to decide on a foul, put a whistle to our mouths, make a decision on playing on, motioning to play on, and then weighing up whether to blow - knowing that if he left it too long the Spurs players would complain. All in front of 50,000 people, millions on TV, and in a high pressure, adrenaline fuelled match. The rule for advantage used to involve two arms, but was changed so one is allowed, because it was needed so quickly and it wasn't physically possible for refs to move their bodies in the time. All in about a second from the first non-whistle, to the actual whistle. Most of us would probably have tripped over our own feet, as our brains tried to work out what to do.
Yes, we expect the best referees to be able to make very quick decisions, but I see it as three in a very short space of time, and it looks to me like he's just been too hasty under pressure.
Slight flaw in your argument. What possible reason would the Spurs players have to complain about if Hooper had not blown at all, and Grealish had scored? That notion was not even a possibility.