Though I'm not a doctor, I've worked with some clients that have plantar fasciitis. It's very painful when inflammed and seems to be 'chronic' once it begins. It's my understanding that as long as the pain is tolerable, the individual suffering will be okay to go about their daily activities. My clients with P.F. typically can finish a workout and live normally.
Have him see a Doctor ASAP if you think it's PF. You will at least know how to go about treating it.

