The numbers don't tell the actual story of the fight though, they were visibly not competitive and there is more to being outstruck than just the actual number of strikes landed (especially because FightMetric records glancing blows to the chest/shoulders)... Kampmann's strikes were clearly more
effective, as they rendered Diego's face into a bloody mess, and furthermore, he stopped literally all of his takedowns.
I really don't see how you could score those as 10-10s. 10-10 is like GSP-Hendricks R1, or one of the rounds in Henderson vs. Melendez.
Bloody mess doesn't mean anything. There was a reason damage wasn't a part of the judging criteria. Visual damage is an indication of effective striking. But a lack of physical damage doesn't mean striking wasn't effective. So visual damage can be misleading. Furthermore, damage is cumulative, but rounds are scored separately.
Kampmann's strikes were more spread out. He was picking at Diego and countering. Diego's strikes came in flurries. You talk about glancing blows, but Diego wasn't just landing a bunch of glancing blows. He was landing some big flush strikes. He hurt and even staggered Kampmann. So it's not as though Kampmann had effective strikes and Diego didn't.
Also, for such a robbery, why were there so many media members and fans with contrasting scores?
Hell, look at the contrast in scores from the 3 who scored the fight for Sherdog.
Chris Nelson: 10-9 Kampmann, 10-10, 10-9 Sanchez (29-29 Draw)
Lutfi Sariahmed: 10-9 Kampmann, 10-9 Kampmann, 10-9 Sanchez (29-28 Kampmann)
Mike Whitman: 10-9 Kampmann, 10-10, 10-9 Kampmann (30-28 Kampmann)
While nobody gave the fight to Diego, 2 of them had round 2 a draw and they were split on round 3.
While the fans who thing Kampmann won usually call it one of the worst robberies ever, unlike fights like Phan/Garcia I where everyone pretty much agreed on the winner and the round by round breakdowns, in Kampmann/Sanchez, media and fans alike were split with many giving it to Sanchez or a draw to go along with the many who had it for Kampmann.