Had a friendly argument today at work, and the other guy, after running out of things to fire back at me, told me that basically my biggest problem is that I am too judgmental. After considering what he had said, I told him that he was judging me ergo he was being judgmental.
Question: can you call someone "judgmental" without being "judgmental" yourself?

The M-W link gives two meanings for "judgmental":

1 : of, relating to, or involving judgment
2 : characterized by a tendency to judge harshly

#2 is the relevant one, and the key word is tendency. Do you make a habit of judging others harshly?

Yes. Here's the Oxford English Dictionary's definition : "Involving the exercise of judgement [variant spelling: judgment ]; inclined to make moral judgements " The second is its everyday usage, at least here in the UK. The first is only used to describe a particular function as in 'The Roman official's job had two aspects , the ceremonial and the judgemental'.

Ewood has judged very well, I think, without being in the slightest degree judg(e)mental.

However, it is perhaps worth pointing out in this connection a persistent problem in the use of various kinds of characterizing expressions in ordinary language.

Suppose you are driven to distraction by a person and, finally, in a fit of anger, you do away with same. If you are caught (and I hope you are), you will henceforth be labeled as a murderer. But does this single indiscrete act of yours imply that you are characterized by a tendency to commit murder? Or that you habitually behave in this way? Of course not.

The labels we pin on others depend largely on the significance, to ourselves, of the behavior in question. Agentive nouns like "murderer" are highly instructive. Just one murder can make you a murderer, but having on one occasioned danced the frug is not generally considered sufficient to brand you ever after as a "dancer." Nobody cares.

People do care, though, a great deal, about being disagreed with, and especially about being found at fault in some way. So people will commonly display a tendency, amounting nearly to a habit, of pronouncing those who find fault with them on even a single occasion to be "judgmental."

It may or not be the case that the criticism you voiced on this occasion was hasty and ill-considered. And calling you "judgmental" for voicing it is likely to be nothing more than a highly defensive reaction by the person criticized.

What one ought to say, if your criticism is indeed a rash one, is that this particular criticism was judgmental, not that you yourself are characterized by this term.

Why do people not make this sort of distinction when they disagree? The answer is simple: people are too judgmental.

So you can judge but not, in fact, be judgmental. Thanks, Ewood, Fred, and Maiku ; I'm always learning something new here thanks to your efforts.