I wanted to prevent them from tacking to an advantageous position. If we just held course, they would have been able to (and they did) tack in front of us. Giving us a lot of bad air. By footing off, we might have been able to make them tack short, giving us enough room to point above them, and give them the bad air.
The maneuver you suggested to your skipper is perfectly legal and fair. It's basic covering of your opponent. You were starboard, they were port, open water.
Question: Do you really think you could have fallen off and tacked in front of them? If they pulled off a tack in front of you (and if you were both hard to weather before that), then it sounds like they were in front of you the whole time. Falling off to get in front of them would not have worked.
