You are at no more risk trading bitcoin in person than you are purchasing anything in person. Every time you use an ATM, someone could rob you of the cash you just withdrew. Every time you buy some new piece of electronics and step out of the store, someone could rob you of whatever you just bought. Every time you go out carrying your phone, laptop, cash, jewellery, car keys, etc., someone could rob you of all of these things. Take standard precautions like choosing a highly rated trading partner, meeting in a public place, and not sharing any personal information, and it is very safe. I've completely hundreds of face to face trade at this point and never had any issues.