Look at it from Jacksonville's perspective.
My guess is that when Buffalo offered the trade, Jacksonville called Jerry, and told Jerry that Buffalo offered a 4th round pick, and that they (Buffalo) were going to select Kincaid.
Jacksonville was trying to get the best deal they could -- in other words, I bet, Jerry/Cowboys knew Buffalo was going to select Kincaid even before the trade was finalized.
Dallas was not willing to part let's say with a 3rd round selection, or a future pick in order to prevent Buffalo from selecting Kincaid.
Buffalo did not "steal" Kincaid -- they just overvalued his draft stock (Kincaid has back issues at 25 years of age -- so there is risk).
I agree with Jerry -- I will take Mazi Smith, and keep my 3rd round selection today -- more overall better value for the organization.
I don't believe there was a TE from the Cowboys perspective worthy of a 1st round selection.
I bet even if Kincaid was there, Mazi Smith would have been the pick.