Loose means not rigidly fastened or securely attached, and has several other meanings that are closely related to this concept. When used as a verb, it means to set free from attachment or constraint.

I frequently run into sloppy writing in fansubs. They’re produced free-of-charge by enthusiasts that are doing a service to the freeloading public, so slip-ups are to be quickly forgiven and forgotten. This one happens to be a pet peeve of mine, and ironic given the context of the dialogue. Maybe if young people hasn’t lost interest in reading, this travesty of syntax would never have happened.