I had one horrendous experience with a high school production.
Because I was known to be reviewing films professionally while I was teaching, the drama teacher at the local high school called me and asked me to review their production of FLOWERS FOR ALGERNON. I told him I didn't want to because some of the students would be former students of mine, and I didn't feel I could be objective to them. He begged and begged, and I said no.
He was SO insistent that he called my principal and asked him to make a personal request to me to do this. The principal wouldn't take no for an answer. The drama teacher was insistent that he wanted an honest evaluation, not a sugar-coated reaction to their production, so my principal couldn't see a problem. I could be as honest as I wished without fear of reprisal since it was not my idea to do this.
At any rate, I agreed to do it. It was the WORST production I have ever suffered through, a total fiasco. Kids dropping lines all over the place, props left on-stage that others stumbled over, deadly pacing, awful acting by all but two kids, and a set obviously put up at the last second.
Well, I wrote the review and tempered any negativity with the few shining moments I could find. I didn't criticize a tenth of what I could have, and even when I wrote something negative, I tried to give the actor I was finding fault with a little praise as well about something.
You can guess what happend: a firestorm rained down on my head when the review was published in the local newspaper. You would have thought I had raped every child on the stage and left them for dead. I got hate mail at the newspaper from parents of the kids involved and from others not connected with the show and hate mail at my school. My poor parents got telephoned by parents wanting to know if this was where "that critic" lived (I had moved out many years before, thankfully). Worst of all, the drama teacher who had begged me to review the production wrote an impassioned letter to the paper chiding me for my "poison pen" and my lack of support for the school system where I worked! I called him to confront him about his two-faced reaction, but he slammed the phone down on me. FOr the rest of my career, that teacher never spoke to me again.
The editor of the newspaper defended me (he knew the whole story) in a rebuttal, but that was the LAST time I ever reviewed a local production.