First things first,
To check if it is the bearing jack the wheel up put one hand on the top one on the bottom and "waggle" is there any movement if there is its the bearing.
Form B, I agree this is one way to check if the bearing is worn, however, if the top or bottom (if there is one) wishbone ball joint is worn, then the wheel unit will also shake/wabble and it is then a case of stripping the unit down to eliminate the probable parts, to the point of identity.
The guy seems not too familiar with these kinds of problems and I would advise him to take it to an experienced mechanic though, as stated before, safety is paramount mate and if you are not sure then don't go there. It should not cost too much for what will be an hours work plus parts.