It was a really awful attempt at a takedown and was stupid besides. It's not defensible as a strategy, going to the ground where Nate had a huge advantage either on top or on the bottom! Conor should have just kept it standing, maybe gone for the clinch against the cage or circled away until he recovered.
I posted after the one that you quoted, but in a nutshell I agree that guys should think about their safety as far as tapping to submissions. Especially with joint locks! However, with striking I regard it a little differently. You fight until you cannot continue.
It was a bad strategy, then. Miesha had a big advantage on the ground, and damn near finished the fight in the second round. It was a calculated gamble. Conor didn't have an advantage on the ground even if he were on top. Nate has a good offensive, active guard that, even if Conor wasn't rocked, would have given him fits.