Where is the goal from the door?! (Resident Evil 2)

Noticed this time, maybe carp, maybe the developers overlooked or did I missed it, but where is the chain from the door?
Now detail, after Sherri pours the Sheriff's acid, begins a hide-and-seek, in which the Sheriff leaves, we need the key in the door. Taking the key and the chase begins. After opening the first door on the second floor, we go down the stairs to the hall where the open door facing the street, but it turns out to be related circuit on the other side. Then we run back to the Sheriff's office, the movie starts and we begin again to play for Claire. But here's the thing, after all the way, we come to the most linked the door and voila, no chains, go the door is open. At first thought it was sherry's father broke it but it how I understand it got out of the basement.
What do you think?