I was initially horrified when I heard this story, but after seeing the photo you posted, I can certainly understand that these young men did not know this was a Nazi flag. Those just look like stylized letters to most people. For young people who have received a public-school education and haven’t seen a lot of Nazi graphic art, it wouldn’t have registered as anything but a cool way of using the letters for “sniper scouts.”
Take a look at the image in post 52 - suggests that this symbol is more widely known, and not something these guys came up with themselves.
I dont think its being suggested this is an actual Nazi flag - just the symbol.
This is a Nazi ss flag, the one in the picture is not! Note the color scheme.......