The OTSRs caused bruising, internal injuries (for one rider), and a collapsed lung. Lap bars on the other hand would have near enough cut people in half. The forces would have caused much worse injuries (probably along the lines of death and paralysis), and it wouldn't have prevented amputations. I know towers were criticized for having lap bars in the first place, but I think they prevented fatalities.
And looking at those photos, you can really see how well it was managed by emergency services. Seeing how little leg room they had, I'm genuinely surprised that there were only two amputations, and that there weren't any fatalities. Almost as surprising as the fact that they had no procedures in place for the event of a stall. I'd understand if nemesis, or oblivion had nothing in place for a stall, but the smiler has a history of stalling. At least now though, the smiler truly is safer than ever.