AITA for choosing facts over friendship?

I moved away from the town I grew up in in 2022, just about an hour away, but enough to limit contact between my friends and I.

6 months after the move, I (25m) decided to throw a party at my house to finally get everyone together. I invited all my different friend groups, overall about 15-18 people showed up.

My school friends showed up a few hours before everyone else. As more people kept trickling in, the party activities started.

Now let me get to the incident, my best friend (25m), let's call him Kyle, said he wanted to talk to me alone, he said that one of my uni friends just tried to grope his gf (24?f) by putting his hands under her skirt, and I should kick him out and confront him immediately.

Naturally, I am the host of the party, so it's my job to resolve this, the first thing I do is go to see Kyle's girlfriend, Amy. I ask if she needs anything, and discreetly ask her if she can tell me what happened and how she is feeling. Amy brushes off my question, saying that it's no big deal and that the guy was sitting next to her on the sofa, and tried to grab something laying between them, so his hand brushed up against her thigh, she was shocked and scared at first, but then realised what had happened, and said it was all fine now.

Later, I find the accused, Mike (25m), outside, I ask him his version of the story, leaving out the part where he was exonerated. He says he was grabbing the remote and accidentally touched Amy, and that he would never do anything like that, especially with his own girlfriend sitting on his other side.

Our conversation was interrupted by Kyle, who was clearly very angry at that moment, he starts shouting at Mike, asking him why he's trying to touch Amy inappropriately, and yelling to me that I should fucking kick him out because Amy feels uncomfortable. I interjected, saying that it was all a misunderstanding, and I have the same story from both sides, so surely the matter is resolved now.

He was not seeing it in the same way, I have been friends with Kyle for 14 years, and Mike only 2, so I should blindly trust him and kick Mike out because he says so. I refused. He started saying that if friendship means so little to me, then we should not be friends, as I chose some random idiot over him.

After some more drunken shouting from both sides now, Kyle says he is leaving, and taking Amy with him, I gave Amy a jar of my mum's homemade pickles as a parting gift, as she has been in love with them and whenever we talked in the past she would ask about them.

Cut to about 20 minutes later, I receive a long DM from Amy's Instagram, saying that she was just afraid of telling me the truth, and that she had been assaulted, and that she is disappointed and hurt. Now I do suspect that Kyle wrote this from her account, but I cannot confirm it. I apologised to her, saying I am sorry if I missed any signs of discomfort.

That night was our last contact.

So, Am I The Asshole?