From an ESPN article " He was among 17 players invited to attend the first round in Kansas City. Only four of those players didn’t hear their name called: Levis, Alabama defensive back Brian Branch, Penn State cornerback Joey Porter Jr. and Georgia Tech defensive end Keion White."
So almost 25% of the players they thought would be first rd picks didn’t get picked, and actually it is worse than that because they only invited 55% of the total first rd picks (17 of the possible 31).
Point is no one really knows what teams are looking for or direction they will go on any given draft