I can see you all eye rolling now but he is a good man.
Not all violent men, murderers, rapists and so on .... are 'bad' men 100% of the time. On the contrary, most are normal, charming, funny, kind, likeable, hard working, sweet natured and so on. They don't have 'violent pig' tattooed on their foreheads and go around growling at everyone.
How many times have you read 'I never thought he was capable of doing something like that' ....'I just can't believe he could do that' ....'he's the last man on earth I could imagine doing something like that' .... and so on.
Your friend described what he did to you as a 'moment of madness' and that he loves you too much to do it again. So what happens next time he gets a 'moment of madness'? Do you honestly think he's going to stop and go 'oh no, I love her too much so I won't choke her this time?'
Your 'good man' is capable of violence. He's shown it already, twice. The most recent time he put his hands around your throat. Just knowing the man you are living with, sleeping with and God forbid, married to, is capable of doing that, should be enough to have you running for the hills.
Every woman who was persuaded to stay with a violent man, was persuaded by the begging, pleading, promises never to do it again, pledges to get anger management, counselling, whatever it takes'. And no doubt some were also persuaded by the words of well meaning friends and family telling her to 'give him another chance'. But sadly too many of them find out the hard way they should have left after the first incident, and never looked back.
Your friend cannot know he will never do it again, she cannot know anything about what this man is capable of. She is just another outside observer, one of those, who after the event will be shaking her head and saying ''he's the last person on earth I could imagine doing something like that".