I think the only reason I wouldn't call it a TD is I would like to see if Walker (green) stops Molloy's momentum from rolling/ or scrambling out of the position. I agree if in the middle of a period and you have the luxury of more time, any ref would wait to see how it plays out. It looks like after the buzzer, Molloy's momentum was stopped and didn't roll through. Unfortunately, it's not like football when the buzzer goes off you have time to finish the play, and can't call it that way.
This is a sweet firemans, but in a firemans takedown like this, Molloy (red) grabs Walkers (green) head and has it tucked under. Does it matter if he pops his head out or not before you call it a two? In my opinion, I don't think it does matter.
Good point on not wrapping arms around legs or body, but the way they landed on top, Walkers legs have Molloy's legs wrapped so I think that establishes control.
