I think you mean to say, when Alice implicates from "Well, he is capable of doing it" (~13' into the video), that Charlie is not doing his homework, she is following the rule of manner, not quantity. Since you have exemplified the three previous maxims: quality, relevance, and quantity, we can infer that you intended to exemplify the final maxim of manner. Which is, I believe, an implicature of relevance. Thanks for the video!
Today I realised,I unconsciously use so much imperative and performative speech act . I sounded so arrogance and dominanting but my intention was never that