OK... charts/docs shouldnt be left behind but these things can and clearly do happen. Surely 3/4 experienced pilots using FMC data, ACARS, Satphone co-ordination to LHR ATC to see if they will accept them and QF dispatch (or whatever they call it) to validate data for destination and a suitable alternate, Cant be that difficult or un-safe given some 5 or 6 hours to figure it out.
From whats written here the whole thing sounds sloppy. Maybe theres a "back story"