According to me, Monica did play a role in influencing Richard to take the decision. In the episode, after speaking to Gregory and Belson, Richard becomes sick and starts throwing up due to indecisiveness, panic and stress. He then sees Monica in the parking lot. They start talking and she tells him just how big the compression engine idea could become and asks him to take the money.
"This is your baby.This is game changing. Don’t you want to be in the driver seat when that happens?" she demands.
This conversation with Monica would have definitely help shape Richard's decision.