The dude couldn’t implement his patent (downloading media with drm that’s unlocked by a key downloaded from a server). He hired others to do it. His business went defunct. Apple hired one of the former employees to work on something similar because of their expertise. Is that patent infringement?

If someone hires a former Facebook employee to work on their social network, is that patent infringement?

If the patent was obvious to begin with, and there is existing prior art, is that patent infringement?