“They do change them after every customer...”
Are they practicing hand washing between every glove change? If they aren't they can simply contaminate the ‘fresh’ glove. The same as spreading contagions through food preparation.
“....It has been demonstrated that both the interior and exterior of gloves can become contaminated with surface hand microorganisms if the hands are not washed prior to gloving (Docket C-3). Hands themselves can also be contaminated with organisms found on the glove surface...”
There were several threads over the w/e about the type of glove, one guy who posted is a chemist & gave a pretty clear explanation.