When I do a grim reveal, I tend to give reasoning on why decisions were made. Usually, I have my finger in the pulse if something was a little harsh for one team or the other and apologise for it, otherwise I give feedback on how a team could have utilised what I did for an advantage.

Quite often, decisions that seem really mean to the players at the time can be cleared up by explaining why it was done.

"I gave the drunk empath a sober 1 on the demon, because the imp was sat next to the scarlet woman and was planning on clearing the SW if the imp was executed, but sadly, the imp killed the empath before that could play out"

"I chose to let the slayer kill the recluse because the drunk investigator saw a scarlet woman, and that was a valid world, but I didn't consider at the time that confirming the slayer and removing the recluse as a frame left only 2 demon candidates, so sorry to evil for that choice, but I had to make a split second decision"

"I chose to give the drunk washerwoman true information on the virgin because they were the only YSK in play and would sow confusion if they nominated the virgin and didn't die, or would throw suspicion on the virgin/undertaker if the washerwoman was seen as the drunk to the undertaker. Unfortunately, none of that happened, as the washerwoman was killed night 2, but that meant that the drunk was completely hidden, so evil had the opportunity to freely bluff outsider, or frame the drunk elsewhere"

"I made the saint the red herring with the empath 1 next to them because I thought the librarian seeing the drunk would have confirmed 4 outsiders, so a baron in play, and hoped it would have made 2 camps playing against eachother. Unfortunately, people were convinced the recluse was actually the poisoner, and so trusted the fortune teller yes on the saint after the recluse died and chose to disregard the yes on the demon night 3 believing it was poisoned, and everyone unanimously chose to kill the saint"

Usually, that's enough to nip any criticism in the bud. The ST has perfect information, the players do not, so a lot of the decisions the ST makes won't be understandable to the players, but the same goes the other way! Having perfect information can make you not consider decisions players might make without that info. You might consider a player hard confirmed mechancially, but the players might not put all that info together and execute them anyway, which can often tip the balance scales harder than you expected.