An embarrassing moment

I set out for a walk this morning and M says he will follow. Later I turn around to see him coming up the road with his head bent down.
 
Then I notice something odd. He is walking with his toes turned out, pigeon toed. Why had I never noticed it before? After all we have been married for 50 years. This must be a new ailment.

When he is within hearing distance, still with his eyes fixed on the ground, I call out: 
“You are walking pigeon toed.” 
He looks up. His eyes meet mine.
It isn’t M.
He smiles.
“I know I always have.”
Well in my defence all I can say that both men are the same height, wearing dark anoraks and trousers, beanie hats and thick gloves. And it’s a dark dreich day.
He is a total stranger. I apologise. He walks on.
 
What is your most embarrassing moment?
PS Later I learn the correct term is “duck-footed” - toes turning outwards not pigeon toed which is walking with toes turning inwards .