Did Obito abandon his 'ninja way' when he adopted the Tobi alias? His ninja way was:

"In the world of ninja, those who don't follow the rules are scum, that's true. But, those who abandon their friends are worse than scum." - Kakashi quoting Obito

If Obito truly believed this, why did he seem proud when Sasuke stabbed Karin to get to Danzou? Obito seemed to like this, and when Sasuke attacked Sakura with his Chidori. This seemed to go completely against Obito's 'Ninja Way'.

I know people are going to say that he has more important things to be concerned with and he has evil intentions now, but look at Hanzo. Hanzo stuck by what he said and praised Mifune for doing the same, even sparing his life. He was a leader in times of war, who had a much bigger mission, but he still kept to his 'ninja way.'

Any ideas?