You can also find information on Know Your Rights and what are the scenarios to apply by going to http://driveca.org/toolkit/

But, overall, it seems like there will be discretion used when evaluating DL applications. It is a big concern for the community, but as long as your dad used the DL for driving purposes only, it might be fine. Best thing is to wait some time (6 months or so) before applying, to get a better understanding on how the DMV will deal with this.