Three Flags Trike

I have observed this fellow on his trike with its flags around town on several occasions.
While on foot, with my camera, between errands today I had the chance to make a photograph of him as he rode past.
When I looked closely at the image at home I realized the USA flag is hung upside down between a US Marines flag and a Vietnam POW-MIA flag.
I continue to think about this man who makes this display part of his existence every day he rides his trike.
It makes me melancholy to say the least.