You probably already know this, but remember that all outlets need to be tested for physical and electrical compliance after installing and every year in most cases. In addition, most biomedical engineers believe that less than 50 mico amps difference in ground potential between two outlets can cause fribulation, so grounding is very important. It shouldn't be a problem because biomedical electronics is suppose to be tested for compliance to not let this leakage kill someone, even if it exists, but why take the chance? 50 micro amps is far below the amount that you could ever feel so the 'finger test' is not going to do any good.