That's very true DL but I qualified it by saying intent is a different matter. I take your point however and in hindsight, it was a reckless challenge and therefore dangerous, so in the modern game Red was correct. I am still appalled with the effect these red cards have on the game that thousands of people pay a lot of money to see.
How about this: Send the offending player off for a reckless challenge ok but if it is clear that intent to injure was not the motivation then allow the team to replace him with another player. Thus you punish the player but not the team or the fans by spoiling the game. There are far too many red cards in the game nowadays and they have far too big an impact on the contest to be fair.
I know that the Arsenal fans were probably quite happy with the game, but even they would have preferred to have beaten Spurs with 11 men instead of the slightly tarnished win against 10 wouldn't they?