I'm sure he appreciated that.

I saw a guy stand on his platform pedals on a rainy day while pulling away from an intersection. He slipped and it appeared his family jewels had an unpleasant impact on his top tube.

I refrained from telling him that that's why I ride clipless.

Actually, I use both clipless and platforms depending on which bike I ride. There are pros and cons to each. I've fallen over because I've forgotten to unclip. I've slipped on the platform pedals (though my current ones have plastic pegs). I've also managed to avert a fall or two because my feet were clipped in and I was able to maintain/regain control.