Honestly neither of them deserved to win, that fight was pretty awful, but if I had to pick a winner I think it was Murphy.
Why? Because she was actually fighting. Actually hitting her opponent, actually making an effort to do damage (even though she didn't really do a whole lot of damage).
McMann did nothing but stall in that fight. It would be hard to find a male fight with more blatant LnP and the fighter on the bottom landing more and working more from the bottom throughout. Mousasi vs Mo, Schaub vs "Big" Johnson, and even those at least the top guy had some power to offer.
Unlike MMA judges I do believe it is possible that being on top does not automatically mean that fighter is winning.
***If the title was "Who deserved to win based on precedent of prior mma judging outcomes?" then I might have had to pick Sarah.
I'll admit the fight was so boring that I wasn't glued to the screen taking in each and every moment in great detail, but what i do remember was McMann doing NOTHING on top while taking strikes from Murphy the whole time. Even though they weren't big strikes, they were landing and they were landing often.
If it was a standup fight and a fighter landed 3x the amount of strikes as their opponent, (assuming no KO or near finish, which there was not in this fight) they would win without question, even if the strikes were not all that hard. So why would these strikes taking place on the ground change that?