[quote=@Schradinger]
How did Isa get out from underneath him? You seem to go from him sitting on her stomach straight to the triangle choke with no transition from mount to guard.
[/quote]

because as she rolled back as he stood up she threw her legs back, he wasnt in a full mount to begin with, he was only in a  postured up mount inside her open guard.

I'll find the quote:

[i]'As he mounted her, she used the backwards momentum to keep her legs apart and raised them in the air as she moved to her back'. [/i]