[Alpha]

Heard it is a grey area if they use their cell phone

It's only a grey area if the cell phone number used for business is listed on the do not call registry, AND the call was initiated by an auto dialer program. If it was a hard dial initiated phone call to a cell phone listed on the do not call registry used for business, it is an exempt business to business action. Judging from this guy's court records, he is fishing with his lawyer for a large class action lawsuit, and making the assumption that is was an auto-dialer initiated call, or hoping that they can shake you down for a settlement assuming you are not familiar with the laws they are trying to manipulate into a payday.