Can dropping a phone or slipping my hand onto my face, cause damage or shift a chin implant/change the outlook of a rhinoplasty?

I think it is very unlikely that you caused any damage or shifting to your chin implant when your hand slipped onto your face.  It normally would take a good amount of force to shift a chin implant or damage a nose in the immediate recovery after surgery.  If you have a concern, you should see your surgeon so that you could be evaluated in person though.  

I am glad dropping your phone onto your face 2 hours after surgery wasn't painful. I will change my personal post-operative orders to warns patients of this risk.
Routinely a pocket is formed for the implant to fit into, so I suspect there will be no shifting.
Be careful.