The real shame is you went on a beautiful vacation and ended up in an argument with your spouse. I hope you don't resent your spouse for getting up and leaving, especially since you put yourself in the position to swim while not mindful of your environment.
Also, a back-float is always generally a good strategy in salt water conditions when you've lost control or strength to swim. You carry over common waves and it takes very little energy.
Yeah, I'm having a hard time seeing how laying on your back to catch your breath is a bad idea. I thought everybody did that when swimming for extended periods of time.
The parent does mention swimming against a rip current, which would explain the need to swim at maximum physical exertion for an extended period of time. In that case I don't think he panicked.
Also, a back-float is always generally a good strategy in salt water conditions when you've lost control or strength to swim. You carry over common waves and it takes very little energy.
Honestly, it sounds like you panicked.