I don't think I 'failed to yield' to him because I exited the intersection before he entered it: he only really had to slow down once he got into the road I was in. But had he given me a ticket for that, I might have just taken responsibility and paid the fine. I mean, I think I could plausibly argue the case in court because I "made it" well ahead of him. But then again, he may have started slowing down much sooner, and it could be a thorny argument.
What interested me most about it at the time was: it was a 3-way T-shaped intersection formed by taking a 4-way intersection and blocking off the North end with construction work. So the North-South road had no signs, but the general rule for such intersections (and I think it's explicitly written down in most states, but I'm not sure) would be that the South traffic has to yield to East/West traffic: in other words, in combination with the East/West stop signs, I think the law-books would imply that the road should have implicitly become an all-way stop.
Apropos of anything else - you DID cut him off, and you did fail to yield (Stop signs are also Yields). His argument about you running the stop sign is invalid, sure, if you were at a complete stop, but if you're forcing someone who did not have to yield to, by your own words, 'slow way down' to match you pulling out in front of them, then you were in the wrong.