He tried multiple times and couldn't manage to get him in one, which really worries me. If someone tried to fight out of his clinch the way that Nick did here, Silva would just lock it in and punish him. Didn't happen here.
He's got mobility, the technique is still there, but the power, precision, evasion and viciousness that used to define Silva's fighting style all seem to be diminished to varying degrees. We didn't see the return of Anderson Silva tonight, we saw the arrival of a pretty good fighter that just happens to look like Anderson Silva.
The Anderson Silva we all know and love is dead until further notice.