Is this plagiarism? (Update: jury says no)

I personally don't hear it but I never heard it in that Robin Thicke song either

That song actually involved a straight sample from the Gaye track itself. It was literally taken from the Gaye song.
Totally agree with Chuck. I really don't hear anything in Sheeran's track. However, someone should've lost their job for allowing Thicke's track to hit the market without some type of credit/compensation to Gaye's estate.

On a side note, that estate likes to sue folks...