They say 9 missed tackles for Brooks. Having watched the game it really didn't seem like he had a bad game defensively when the stats would suggest it was one of, if not, his worst game ever.
They must be counting all the times he rushes out of the line or on a kick chase where he gets to the attacker first, slows him right down, but the runner wriggles free only to be jumped on by 2-3 other defenders shortly after. I wouldn't count that as a missed tackle as he served his role for the team making the tackle, albeit he dropped off a second before the tackle was completed.
It's these differences which can skew stats against the likes of Brooks and Moses. I'm not saying they're great defenders but these stats can exaggerate their deficiencies.
I'd be curious to know how many of his missed tackles lead to a line break, line break assist or even a lot of metres made by the player. Those misses are usually glaringly obvious. The lack of those is why you can't look at stats as black and white as a true indicator of performance.