I think the 'his studs were up!' is such an overstated and hysterical way of refereeing a football match (a bit like, 'He raised his hands! You can't do that."), so I'm inclined to think that Brooks, like Oliver in the previous week for the Doku challenge on Mac Allister, called it right. Having your studs up should not by definition endanger an opponent, but only when the tackle itself is forceful and reckless.
It's virtually impossible to play the game without your studs being visible. You should be able to compete for the ball with your boots and that will inevitably result in high studs up challenges.
There was nothing particularly reckless about any of the challenges that necessitated a red card (nor was there in Doku's the previous week). McAllister's you could argue was a yellow but it would have been soft.
If two players go for the ball with their heads and clash to gether, and it looks like the Doku challenge or the Gomez one, nothing much is said. Why should it be any different with feet? In most cases, studs up challenges don't result in injuries unless they're wild and reckless. A bigger problem in football is scissor challenges which are often viewed as fair, but they cause more injuries by far.
I think Brooks and his assistants MO was basically to let the game flow and that he was consistent in that regard and it produced a better game of football. He called the MacAllister goal right and got most if not all of the big decisions spot on. Diallo's red was unfortunate but refs get pilloried if they don't punish players who remove their shirts.
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