First, I assuming you are talking about Gym teachers in High School and below who may be touching minors. In any and all cases, touching a minor is recipe for disaster, however, there are situations when you will need do it for safety reasons....which with witnesses should be a reasonable defense in the unlikely event things get misconstrued.
With adults, its a little less risky, but I follow the same basic premise. I try to minimize touching unless it becomes a safety issue. The most challenging time comes when we do CESA. I was taught and perform a CESA with the students BC shoulder harness in my left hand along with the float rope. Should their be an ascent issue, I can squeeze down and stop the ascent while having my right hand available. When working with females, especially full figured females, I first tell them what the plan is and I carefully locate a position on the shoulder strap that is as least likely to be misinterpreted as possible....sometimes, there is a D-Ring convenient and I lock my fingers throught that.
In summary, I minimize touching....if its planned, I forewarn them and make sure they are comfortable with that, and if its an emergency, I do what I need to do to insure safety and let any touching issues be addressed afterwards.
Otter