But the pick was used in the first round to draft that player.
The Bills could have drafted a lot of players with their first round pick at #16. They drafted EJ. They could no longer draft anybody with pick #16. Because it was used to draft EJ. The drafting of EJ was done with pick #16. Pick #16 is in the first round. They no longer could draft a player with pick #16. Pick #16 was spent, used, bartered, offered, to draft EJ. EJ was drafted, selected, picked, acquired with pick #16. Pick #16 is a first round pick. EJ cost a first round pick, which is pick #16, which is a first round pick. There is no such thing as less than a first round pick in the first round. They are all first round picks, with differences in value. But they are all first round picks. Or else they would be picks in other rounds. Every player in the history of the NFL drafted in the first round cost AT LEAST the first round pick used to select them. You cannot be drafted in the first round without costing a first round pick. Or else you wouldn't be drafted in the first round.
Pick 1 and pick 32 are both first round picks. Every single player drafted 1- 32 cost picks 1-32. Picks 1 - 32 are first round picks. The first round consists of picks 1-32.