When using the word remiss to denote a failure of action, is one remiss in the obligation or is one remiss in not having performed the obligation.
e.g. I was supposed to go to the grocery store today but did not get around to it:
[ul]
[li]I was remiss going to the grocery store[/li][li]I was remiss in not going to the grocery store[/li][/ul]
If you were supposed to do something but didn’t, you would say you were remiss in not doing it.
If you were not supposed to do something but you did, you would say you were remiss in doing it.
So the answer to your original question is affected by the context. In my experience, the word is most commonly used the first way, indicating negligence in not having done something you were supposed to do.