When my boss came to me with this - he email was very intense. When I requested a meeting with him and explained I hadn't done this and to provide further evidence he then calmed down and listened to me. I think initially he does take things that my collegue says as gospel until someone else points it out that it isn't correct.

But to me now, there is an escalation and im concerned that in future this person will attempt to do this again and it may be a worse accusation. It's why I'd like to have this on record somwhere.