a query for the frequent players

I'm looking for examples where a Co has reported lab sourced composite assay results that they have subsequently altered with a significant outcome.

I'm well aware of the myriad of in-house issues regarding meaningless XRF numbers, dodgy interp, loose descriptions of mineralisation, directors specials, etc, etc, and I agree with anyone who thinks all that needs cleaning up. But right now, just looking for seemingly bona fide assays later found to be wrong.

Cheers