Problematic behaviour from co-worker. Manager ignoring problem

theoretica

What you can control is your behaviour. Can you make sure if he snaps at you again it doesn't lead to an argument? Can you do your job with headphones on?

dandelionclock30

It sounds to me that he might have clinical depression to be carrying on like that. I bet hes on some type of performance plan with them but they cant tell you because of confidentiality.
If your really fed up put in a formal complaint and they have to respond to you about it.

DaveTheMus

I have to say that I much prefer a moody, grumpy old curmudgeon who is vocal with his grievances and gets things out in the open.

I cannot abide people who are nice to someones face but unpleasant about them behind their back and don't have the strength of will to tell someone directly that they have a grievance with them.

You know where you stand with the first guy, not so much with the second.

asajj

If he has an health related issue - perhaps he should be given some leave by doctors / company.

Noone has the right to make your day unbearable and your company should maange this.

I'd speak to HR directly.