Yes it could matter but it shouldn’t matter. She’s been there 8 years, he’s been there 4-5 weeks.
As @spookehtooth says is right. OP is lucky as she has a HR dept which a lot of smaller companies don’t have.
I’d even go so far as to print/link emails in my HR complaint about stalkers to HR.
Many years ago when I was 24, I was stalked at my workplace. I was a float secretary for a big UK wide removals company called Bishop’s Move. One of the removals men who was 7 years younger than me fancied me and we had a fling, a few of the office staff did this with the removals staff. Then we broke it off or I did and I noticed he was following me to the station after work.
He almost always followed me in clear sight or relatively clear sight but a good 5-10 minute walk away. He wouldn’t leave me alone. It was mostly trying to talk to me which I didn’t want to do. Luckily, after a few months of doing this he stopped. Also, fairly luckily, on a few occasions some of my colleagues who caught the same train as I did were walking with me. But if I’d been for after work drinks he’d follow me from the pub. I knew if I said anything all his family (his dad worked there and his uncle) would’ve accused me as being a trouble maker.
Luckily, though he knew the area where I lived, he didn’t know my address, and I don’t think he’d have followed me home, which was about a 30 minute train journey away. He did threaten to get on the train with me though.
He lived with his family across the road from the offices. It was quite scary when it was darker though as I saw him a few times where he was hiding from me. But this was in the 90s, when stalking wasn’t really a thing so I just hoped it went away. No HR then either, you could’ve mentioned it to office managers or the MD’s office but that was it which was surprising for a large company.
It’s a scary experience though, and I’m lucky I left not long after this (not because of this) and I didn’t see him again.