Pain specialist conducted emg/ncv. said if legs cold would return inaccuracies. only warmed up leg that was not of concern. mistake or intentional?

Depends : Your answer depends on why test was taken, & what you plan to do with the result. If test is intended to decide whether you will/will not benefit from surgery for a potentially disabling nerve problem, then you should have the test repeated if test result was unclear. If the test result is not decisive or the illness is not significant, then you & clinician can just discuss appropriate actions.