Wrong place at the wrong time in a Northern Irish border town about 7 or 8 years ago. Bloke lying in the street barely able to breath and bleeding from the head. I decided to stop and administer first aid while others walked on by. Turns out he'd been given a doing by a group with a preference for the Gold, White and Green who were standing over the road watching him die and I was spoiling the fun. It started with them throwing coins and hurling abuse at me and telling me to leave him and then got slightly more serious. At that point I uttered the most stupid words of my life "shoot me if you like but I'm going to help the guy", they recognised I didn't have an Irish accent and asked me where I was from. They then said I was very lucky I was a Scotsman.
Ambulance arrived with an armed escort, barely checked the guy over before loading him in the back and getting out of there quick smart. Officer turned to leave and I asked if they wanted a statement to which he replied "not unless you have a death wish - I suggest you head home for the night".
I also faced a similar, but not quite so brutal, situation after wandering off the main streets in Philadelphia where the discovery that I was a Scotsman turned me from a victim into some kind of long lost best friend of the guys I bumped in to....lol.
Being Scots has become like a security blanket for me and I make a point of pointing it out wherever I travel, and it never fails to amaze me how attitudes change when people realise your not British or English.