I don't think most people ride without a leash "to be cool", its bloody liberating not wearing a leggie. I personally hate them.
But you've got to measure the situation, if the waves are faster and there's a crowd then yeah, you need to be considerate and wear one. But if there's 3 or 4 out and its mellow then ditch the leash, still be cautious and enjoy the freedom

I still always take one and throw it on the beach just in case.
BTW, if the Hipster chic was a mc'hotty you totally would have rescued the board

But is was actually Lacey wasn't it, having another fued
Personally, I would have rescued the board, responding to a duesh by being a duesh isn't the answer, I would have then handed over the board and politely pointed out that the conditions weren't really suitable for no leash... but thats just me