Like I said, I'm sorry but it just smells like a marketing scheme to me.
At best, he's telling the truth and has some secret techniques that Bruce didn't want to share with the general public, right? So he's turning around, banking on Bruce's legend, and selling those techniques to the general public -- which Bruce specifically didn't want to do. I find that distasteful, on a personal level, as something to do to a friend and teacher.
At worst, he's making the whole thing up. He might have some cool tricks to show (like Guro Dan certainly does), but instead of admitting they're his cool tricks, he's marketing them as Bruce's cool tricks in order to name-drop and make more money off the whole thing.
At any rate, my opinion on the subject doesn't matter. My old teacher was a Guro Dan student, and as he always told us, the knot of talent and enthusiasm around Bruce is something that's not going to get untangled thirty years after he died. Everyone Sifu Lee taught, and everyone he learned from, and everyone he sparred with, could probably murder me with their pinky finger, regardless of their age...
...but they're still just people. Any of them that we've heard of, we've heard of because they've banked on their connection to Bruce -- to one degree or another -- so it's not like I'm condemning just one guy, or anything.