I don't think there is a 'correct' decision, when it gets complex you just have your decision having balanced everything up.
Eg yesterday, U17 game, challenges in the scrum with opposing FR, choose not to listen in terms of height and binding (both decide it's each others fault), that ends in some niggle, a warning, then handbags so 2x YC. I didn't want the first phase after they came back on to be another scrum and risk more aggro, so I tried to 'manage' the 7 minutes being up to better suit me. Ultimately I couldn't get away with it as crap conditions and scrums everywhere.
The by the book decision is bang on 7 minutes, but you might want to redefine 'correct' to suit!