Just my opinion, but I don't see a problem. Pornography isn't illegal. I presume the work isn't dangerous, ie unsafe working conditions. I'm pretty sure they don't intend for him to be perusing the materials. And in our area at least, the employers willing to hire on recovering addicts and/or cons are extremely rare.
Disclaimer: My opinion is almost certainly influenced by the fact that my alcoholics and addicts have not been involved with prostitution or addiction to porn.