It is very frustrating that I have to repeat this over and over: if the hologram was not sentient, it makes absolutely no sense whatsoever for him to do or say things that the Doctor didn't program him to do. It is illogical. It is stupid. It's like the episode was written by children or for children, so the idea was to make everything as simple as possible, even at the expense of sacrificing logic: if we make a hologram based on a database about Moset's medical data, then it has to look like Moset, too, and if it looks like Moset, then it has to act like Moset.
DE:
1. The program of Moset was simply acting in accordance with the behavioral historical record. That is before Moset was given knowledge of his real life crimes (that Starfleet wasn't aware of), it could very well be that it was public knowledge to some that Moset was a bit cold hearted (after one were to get into a deeper conversation with him). This could have played into his more real to life behavior after the Doctor had given him new knowledge of his character. In fact, prior to the Moset Hologram learning of his real life crimes, it is already shown or hinted that Moset is a bit unsympathetic or coldly methodical in his medical procedures when it comes to attaining his medical goals.
2. The program of Moset defends himself saying he didn't do the crimes that the Doctor mentioned and he is simply a hologram. Now, as for the Moset Hologram taking on the beliefs of the real Moset: it's quite possible the program was simply being adaptive to being more like the real thing when it was given new knowledge of it's character from the Doctor. In fact, in TNG's "11001001", the Bynars enhance the Enterprise's holodeck to make the holograms become more adaptive and seem more true to life or real.
3. It is not an impossibility that whoever recorded Moset's behavioral records into the Starfleet database did it a little too well. Maybe the person who recorded Moset's behavior interviewed a few people who might have suspected Moset and or didn't like him. Maybe a Maquis spy back in the Alpha Quadrant hinted at the truth of his real behavior in the Starfleet database before Voyager got lost in the Delta Quadrant.
Anything else might be too complicated for the viewers to understand, let's just keep it simple.
As you know: communication or getting your plot point across is an important goal for every script. So, in Voyager's "Nothing Human", we learn that the plot point was to show us the ethical struggles when using knowledge obtained by unethical means. In other words, lets say the Moset Hologram did in fact act more innocent and or become horrified as a result of hearing his real life crimes; how is that going to service the conflict of the story line then? Especially when Moset is the very personification of that idea.
The Starfleet database was partial and flawed in that it didn't contain any data about Moset's crimes, about the way he got his research, and it also had no data about his real personality.
Kim says... "Computer: transfer all reference medical files to the simulation."
The computer replies... "Transfer complete."
Kim then says..."Now install
personality sub routines and voice approximation."
In fact, it was Janeway's initial idea to use the medical database and combine it with a real life medical specialist based as close as possible to the real person within the form of a Hologram.
There is no way that any of that information could have become a part of the hologram on its own, if it wasn't in the data that the Doctor used or if the Doctor didn't add it on his own, which is obviously not the case. For a sentient hologram to start acting like real Moset for no discernible reason is really far-fetched and inexplicable; for a non-sentient hologram to start acting like - presumably - Moset would, rather than what the Doctor would want his assistant to act, is impossible. Unless a wizard did it.
1. The Holo program could have been adaptive in wanting to become more like the real thing. Just like the Doctor became more adaptive and grew outside his original programing.
2. The person who compiled Moset's behavior for Starfleet, did his job a little too well (without confirmation or knowledge of his crimes).
3. A Maquis spy could have added a subtle but true record on Moset's psychological profile into Starfleet's behavioral database.
Oh, and as for the morale difference between using Borg technology vs Moset's knowledge:
1. The Borg don't act in malice. They are like a storm. They're very existence is to assimilate. It is who they are. Granted, it doesn't seem right that the Voyager crew would use Borg technology because it is from destroyed civilizations or worlds. However, the Borg have been a lethal enemy of the Federation. And gaining any tactical edge to defeat them, especially in the Delta Quadrant has less to do with morals and more to do with survival than anything else. Besides, none of the Voyager crew are deeply effected in any way in using Borg technology in order to defend or help the ship.
2. The existence of the Moset program is a different case. People on board Voyager had been deeply effected by the cruelty of the Cardassians. In fact, they became outcasts of the Federation because of them. Letting the Moset program or his knowledge continuing to go forward would essentially be an insult to everything that the Maquis used to be and or stand for.
Sources:
http://memory-alpha.org/wiki/Nothing_Human
http://memory-alpha.org/wiki/11001001_(episode)
Using that logic, I don't know if we could condemn Crell Moset, either: there's no evidence that he acted out of malice, that he wanted to hurt the Bajoran patients he was experimenting on; it's far more likely that he just wanted to get the results and didn't care what he did to some Bajorans in order to get it, just like the Borg want to add technological distinctiveness to their own and don't care who they hurt in the process. 
