Indeed, he claims he achieved his results by working out 4 hours in 28 days.
Even so, working out 4 hours per week without changing your diet or just working out in a "semi-competent" manner will probably not bring you the results he claims to have gotten.
You should at least familiarize yourself with the claims before denying them.
Is that measured as door to door at the gym? Weight room door to weight room door? Or time on the iron?
If you measure time on the iron, it is very short. The reality is a lot of your time is spent between sets, recovering, and then showering and changing afterwards.
A 20-30 minute workout a few times a month is much less than anyone expects to spend on exercise for dramatic gains, no matter how you slice up the time and how much ancillary stuff you include in the "time at gym" equation. All of the classes at my gym are ~60 minutes. I'm doing Occam's Protocol from the book, and I get in, do my lifts, shower, and get back out, long before those classes finish their workout. And, I go much less frequently than I thought was necessary: a couple times a week. I haven't been doing it long enough to know what the results will be, but the science is solid.
Even so, working out 4 hours per week without changing your diet or just working out in a "semi-competent" manner will probably not bring you the results he claims to have gotten.
You should at least familiarize yourself with the claims before denying them.