I have a 99.9% pure gold ring which is pretty soft so it gets misshaped easily. I went in and asked him to bend it back to round shape. He told me that I would loose a bit of the gold doing so. I said ok thinking it would be a nominal amount I later had it weighed by another jeweler and it was certainly not nominal loss.
I'm not an expert but I have since bought a $5 mandrel and reshape it myself when needed - no loss of weight.
I hate to accuse anyone but I'm pretty sure this guy stole just a little gold from me. Just a little.