I think the two seperate occasions were linked, meaning, the first guy gave info the the 2nd. You got really lucky. I've smoked in public a countless number of times and only been caught once, but i got off coz it's England. You can get away with it and when you do it feels amazing, but the opposite sucks. Use your best personal judgement at all times, good luck in the future, i hope you never have another encounter with the feds.