Most likely I would bet money on:
gunt had the money and cards in his manpurse, phone etc in his pocket. passport back at the appt.
he was drunk exiting a bar/club and was propositioned by a girl (possibly a pair) for sex/bj
he was then lead somewhere and asked for the money. as soon as he indicated the money was in the bag (by reaching for it) he was jumped from behind by male accomplices. He would have fallen over immediately because he's a fat load. the bag was snatched and he was kicked several times in the face/body as the female exits before they themselves run off.
this all would have 'gone down' in maybe a minute once he was in position. they are not interested in rifling through pockets or trying to take a watch off, its hit and run.
most often its not reported because otherwise they look like a sad john looking for street sex.
A 'drug deal' would be like this:
gunt is offered coke, its fairly busy around so he thinks he is safe.
a little hand me off is done where gunt is given empty foil wrap or something.
dealer laughs and walk off - gunt now notices that a fair amount of the surrounding people are actually 'with' the dealer as they start walking off with him too.
usually they'll say stash it in your pocket or something because of police etc. so they can walk off before you find out but they have no issues laughing in your face if you discover before they are gone.
if gunt tries anything he'd get a kicking but usually its a 'gg bro' and they walk/run away
only the most retarded of people would attempt to get money or the drugs after this.
People need to understand that if you are some rube from out of town especially on your own, its easier and more profitable to scam for drugs than actually sell the drugs. If they get caught they dont have class A drugs on them, its just running cons on tourists.
The fish who just had 150euro scammed off them because they wanted to get coked up isnt usually one to go to the cops either. violence isnt usually involved because more often than not they already have the cash and can just run away.
Rolling johns you need to get physical straight away, this is to ensure the safety of the female so she can depart, the added fact that the female lures are usually related to the other gang members means its probably satisfying to give some loser a kicking for trying to buy blowjobs off your gf/sister/cousin etc.