Hardly. It's just a difference of 10 "levels". My team was once pitted against a #12 or so while we were #27 (or somewhere around that), showing a difference of 15 "levels" even within the same class.
Is 80 the cut-off point between B and C? If so, then you are hovering around that checkpoint, and cross-class match-ups are to be expected. Also, if I remember correctly, either one (or both) of your team or class indicator actually adjusts itself every day, although it doesn't appear to, so it might not be reflective of your team's current standings.
If it were a stellar difference of 70+ "levels", than it might have been a broken match-up. It's not the case, though.