Other than thinking that Yamato simply isn't too smart, the key reason why I think he's not following some plan is the "huh?" reaction he had after Suzuka got mad (or at least, not some master *successful* plan, but rather some poorly thought out idea-plan). To me that says that he was expecting Suzuka to have an "oh okay, that's how it is" reaction instead of getting fed up at him.

Although since this anime goes on on for several (six?) more episodes (or more?..) I'm guessing that details of how things actually happened will eventually get around to Suzuka and she'll have some sort of change of heart.