I had a very nasty moment down a Devon lane some years ago when the passing place was covered in mud.
I wasn't going particularly fast - it was a single track road, but as I pulled in to the left to let the oncoming car through, the brakes didn't respond at all.
My choice was through the hedge or through the gap. I made it through the gap, having clipped door mirrors, but he must have thought I was a loony.
ABS is not all it's cracked up to be, When it doesn't respond you need quick reactions, and most drivers will freeze (me included).
I've had exactly the same experience Dave. Abs does not take into account that, for instance, on some surfaces,e.g.gravel, the build up in front of a locked wheel does help slow you down.
I feel really out of control when the abs kicks in and I don't seem to be slowing at all.
Nick