S-Express
Guest
Never put your safety in the hands of people you don't/can't trust. You can only control your behaviour, not that of others.
This.
Anyway, as far as I'm aware, there is no recognised hand signal which involves stuffing your hand in your back pocket. So in future, the next time the rider in front stuffs his hand in his back pocket, then it is merely an indication that the rider in front is stuffing his hand in his back pocket - nothing more. Once you learn to recognise and accept that, then I reckon you should be ok.
Next week - "My club mate picked his nose and I mistook it for a sign we were being ambushed"