The fact that they have no idea RHEL 14, probably the most well known enterprise distro, is not a thing, and yet they "directly verified on it" casts some doubt on seriousness.
Is it more likely they have no idea what version RHEL is on, or that it's just a typo?
I don't know what to tell you. I'm sure you have them dead to rights on Linux distro knowledge reliability, but the exploit here is real, and the vulnerability researchers they have on staff are also real. Xint is not generally a slop factory.
It's ironic that the one thing LLMs can't do reliably in this space is "write copy for humans" (I don't trust them for that either).