Almost jewelry heist!!!!!!

So today I spent the afternoon with our Curriculum Director who is here from the states for a month.  We got some coffee and did some shopping and I drove us around on my motorbike, I'm a very safe driver and licensed I may add.  We are driving on one of the busiest and well known streets in Ho Chi Minh and all of a sudden Nancy screams and slides forward into me and I plant my feet on the road and break and manage to keep us from tipping over.  I'm like "what the heck happened?"  I thought someone had ran into us or something but no, a younger guy on a motorbike pulled up right next to/behind us and reached out to grab Nancy's necklace off her neck.  So I have read about this happening here and been told not to wear fancy or expensive jewelry but never seen or known someone first hand who it has happened to.  Well it happened today.  It was scary, and luckily her necklace glasp is super strong and he didn't get it but he did manage to pull her forward into me and almost pull us over on our bike.  He left big scratch marks on Nancy's neck where he grabbed and a mark around her neck from the necklace being pulled.  The marks are still there hours later.  If I would have known sooner I would have had her get off and chase the bastard but wasn't sure what happened and just watched the jerk drive off.  I don't wear any jewelry besides stud earrings and a watch but I will for sure never wear nice earrings and necklaces again in the city, that was super scary.  Luckily I am a pretty sturdy driver and there was two of us on the bike otherwise I think we would have gotten pulled off.  People around saw it happen too and were looking after, it was just like out of a movie or something.  But we are both ok and wiser for the incident.  I just can't believe it happened.  I know the poverty here is massive but so many people try to sell trinkets or food on the street and make nothing.  This A-hole could have seriously hurt us or someone else by causing an accident all for a stupid gold necklace.  I will definitely be more careful now.  Wow!