All design decisions involve compromise. Anchoring the lap belt as depicted (for race cars?) above would not provide adequate restraint for aerobatics, and placing the belt optionally for aerobatics reduces its effectiveness for deceleration forces. Note, also, that a reclined seat back with a seat pan that is elevated under the knees will provide good deceleration restraint if the lap belt is tight.
The depiction of the race car driver is a good reference for the belt attachment points, but keep in mind that it doesn't mean the the driver/pilot has to be in a reclined position, as BJC noted, that doesn't work best for aerobatics.
Each aircraft is different, but the relationship between the restraint and the body is what they are trying to point out there. Shoulder harness's should never wrap down behind/below the pilot more than the indicated 10 degrees, it will crush your back. The lap belt should be across the hips, not up into your abdomen. (Personally I think it's depicted in the image higher than it really is used)
And, the attachment points should be, if possible, attached to the the fuselage hard points. In some cases you'll find the lap or crotch straps attached to the seat, but it's always better to go right to the floor with them. Some guys will add a "safety cable" between the seat attach point to the floor hard point, if not an ideal mount.
He's doing well. Surgery on his right leg and foot after the accident. Status so far from Mark G (kit company):
4/24: FYI - I just spoke with Bob and he sounded pretty good. He is drugged up for the pain but was still joking around with me. He is of course worried about being able to fly again. But I encouraged him to let the doctors do their work and let the therapy get him going again.
He said the wire he hit was new since the last time he had flown into this grass trip. No balls on it, and it was hidden by trees. He said the airport had been bugging the power company to put some balls on the wire, but they had not done so. Mark
4/29: Just had a short conversation with Bob. He sounded pretty good. I told him that we needed him here last Friday to help unload the trailer with kits from the factory. He answered that he wouldn't of been much help. I told him that at least he could have supervised me and Mike. We actually used for the first time some "spreader bars" to unload that Bob had designed for us in the unloading. Of course they worked well.
He said that the x rays showed quite a bit of hardware that the surgeons installed in his leg. I asked him if he specified the kind of material that was used. He laughed and said it was probably titanium.
They are hoping Bob can go home to Virginia this week to a rehab place or alternately a hospital if he needs more care than a rehab facility offers. But he sounded good.