Hello please can you tell me if  any one had wrong DNA results with Animal genetics based in Cornwall on border collie’s.

I would guess there there could be a small chance of cross contamination when the sample is taken.
What's the story?

I haven't with that lab no.

what's the general situation?

If we're talking a dog that is DNA clear being diagnosed with the problem some DNA tests while the genes finder believe the gene causes it there can be some who go on to develop the condition still that are not genetically affected. The research papers for the gene/test would should say If this was found. Some tests are more a risk factor test so a dog being clear doesn't mean it can't get it just that it's much less likely.

If we're talking say a dog out of DNA clear by parentage parents has been tested with an impossible result this could be because the pedigree is incorrect. Once reason the kc changed it so it's only valid for 2 gens then you have to retest.