Homunculus did not try to revive a dead person. Why was Homunculus confronted with Truth when Edward gave him the last punch?
it came out from the Gate in the first place, in the piece of alchemy done by Xerxian alchemist using some of Hohenheim's blood. In a way, it has just returned home.
It did perform human transmutation multiple times. Human transmutation is much wider term than you give it credit for but even if we take the narrowest view, at some point Father literally returns the souls of king of Xerses into the bodies he created, mostly as a form of shock tactics to keep our heroes flatfooted. We can say he evaded punishment for that act only because he had God as part of himself then.
As for wider term: the whole process of creating philosopher stones could be seen as human transmutation, a horrible attempt to evade the cost that human transmutation carries. Creation of philosopher stones skims the line of human transmutation on technicality, the same way creation of human chimeras and mobile pieces of armor does. Even if it didn't, Father has enough philosopher stones to undo any and all damage done to him by Truth. Truth makes him blind? Father regenerates his eyes. etc etc. We can also see in the example of Roy Mustang: Roy was forced to do the human transformation but he didn't do it on a dead body, he did it on still living Golden-Toothed Doctor. And changed him into something gooey and wrong but still living, thanks to Pride.
An alchemist is confronted by truth if the alchemist wants to play god by reversing death. Human Transmutation itself (i.e. creating philosophers stones, creating chimeras) is not "playing god", otherwise Shou Tucker or Dr. Marcoh would have seen truth.– RaildexJul 5, 2022 at 9:48
1Human transmutation performed on the living resulting in a trip to the Gate of Truth seems to have only happened twice. There's Roy Mustang being forced through the Gate of Truth by Pride (which seems to have taken quite a toll on his philosopher's stone reserves and is not something he'd have done if not forced) and there's the time Ed and Ling got swallowed by Gluttony. Ed performs human transmutation on himself to get them back to the real world via the Gate of Truth. Both times specifically facilitated via the philosopher's stone. I think otherwise you do need to try resurrecting the dead– GatchwarJul 5, 2022 at 16:28
@Raildex as I have written in my answer, they are "released on technicality". Mayhaps the correct thing is to say "Human transmutation is not forbidden, trying to open the Gate of Truth to return dead to life is. Trying to open it for any other reason is not."– jo1stormJul 6, 2022 at 10:07