Dr. Aoi flew off the handle when Ohara mentioned that she had mapped Maria's DNA structure...
He obviously doubted Ohara's intentions of the genetic map and the fact that she did so seemed like a personal affront to him. He took Maria as a gift from God, sent in humanity's hour of need, and he makes it seem like the took the utmost care in studying her. I have no doubt that he faced a lot of opposition from other researchers who saw Maria as nothing more than 'Test Subject ###' and had far less scruples in how far they would go. There's nothing worse than a researcher with no scruples to see just how dark a human can be. He probably took Ohara as one of 'them' and treated her accordingly.
I think he was afraid of Ohara discovering the DNA coding of Maria's Stigma Body and then trying to 'mass produce' it for lack of a better term - to effectively re-write the base genetic code of humans to produce/develop a 'Stigma Body' in a copy of Maria's. He was afraid of that end result, which is not an unfounded fear - Maria's Stigma Body was natural - what would happen to the scores of test subjects who try to artificially 'create' a Stigma Body?
Personally, I don't know if Ohara was trying to go that far or if she even had bad intentions when she said that - she probably didn't. But the Board of the E-Pandora Project are certainly forcing her down the path she didn't want to go - the path that Dr. Aoi knew that artificially inducing a normal human body to accept Stigma would lead to.
You shouldn't force something to be something that it wasn't born to be [by altering its DNA] - that's encroaching on God's domain.
I believe that was his take on the entire thing.
As for if he is a morally upstanding person/researcher...*shrugs* No one is perfect, but that doesn't mean that someone can't call you out when you're about to do something bad or stupid or worse...
