Robert Baratheon literally tells ned in episode 1 or 2 exactly what Danerys will do when they stop for that picnic. Like, he foreshadows everything that will happen if she has a dragon. He didn't need a red witch or to look into the fire...he knew she needed to die ASAP.
I liked Ned at first but after some time and seeing how other characters in a similar position moved, I hate Ned. Man fukked up so many lay ups for honor.