Rhinoplasty Cast Not Straight; Hence Nose Not Straight?

Correction of the crooked nose (or avoiding a crooked nose as a result of rhinoplasty) is a challenging aspect of rhinoplasty.  It is unlikely that a crooked cast  caused the deviation - likely the reverse is the case

If the nose was crooked at the end of surgery then the cast will appear crooked. It the nose was straight at the end of surgery and the cast was put on incorectly it could twist the nose. Massage or pushing the nose over and perhaps tapling might salvage the problem.

 I have performed Rhinoplasty for over 20 years and the cast will not make the nose straight or crooked but rather is a reflection of what's underneath.  Your nose may be swollen right now giving the illusion of being crooked.  I'd wait for a month or so to see if it's the swelling.  Manipulation or taping does nothing, in my opinion and certainly would not be able to push over the nasal bone and or upper lateral cartilages.  If the nose is crooked after several months, it would require a Revision Rhinoplasty to move the bone, imo.