Walter Scott said it well, "O, what a tangled web we weave when first we practise to deceive!"
Can we discuss theory of things? What a person said under stress is not determinative of the Truth or what society should do. Yet...reality brings another truth. When things get down to one's word against another, many believe consistency is good. Those who hold the same story are more likely to be believed. Under the facts indicated by the OP, people are not going to believe what he is saying beyond a reasonable doubt. Certainly if one narrates a believable story while the other says blah, blah, blah he is bad, that could be changes. Usually after time to settle down and get off the chemicals with a lawyer's supplied nice dress or suit, many can weave a believable tale.
If the OP wanted something done, it should have been handled before all the selling of the sizzle other than the steak came in. We understand the lie of the abused where the other is sure to change. Everyone does. Everyone has some example in his life. But, the time to stand up is when things happen. Not a long time after when you realize you were wrong.
Theoretically? No reason. Realistically? Yes. When we do have cases that disagree with that, it is when the person (usually a woman) reports one thing up front and then changes the story later. We "know" what happened and know how people believe. Far more rare is the sociopath who claims no problem up front than the scared person who immediately says there is a problem and then realizes the actual consequences of such a claim.
Yes, I said sociopath. I don't claim the OP is such. But, the backwards way makes me consider such.