Some years ago I saw a -800 in a repair shop after what - in an outline - sounds like a similiar occurence. Root cause reported was W&B mess-up with subsequent mis-trim for departure. Trough no initial fault from the flight deck, during TOR A/C pitched up so high that tailstrike ensued.
Sky Airlines at Dortmund
BFU Report
PPRuNe Discussion
A tailstrike at 80 knots? I'll be really surprised if this isn't the same mistake. Depressing isn't it? The same mistakes doomed to be repeated over and over again.