You did the right thing walking away. It's your money. And I heard a rumor that Ford will be making trucks for at least another year or two. I also heard that there is more than one truck for sale, somewhere. The 2016 trucks are being replaced by 2017 and deals are there to be had.
Don't be emotionally attached that THAT truck. I've made many an offer for trucks and been turned down. And for cars, boats, planes, etc... I've had salesmen and sales managers chase me as I walked out saying OK, OK, we'll take your offer. I've driven home and as I was pulling in my driveway the phone rang saying OK, OK we'll take your offer.
It's not the only KR out there. If you don't feel it, don't do it.