I also recently did a hair mineral test.
And my cobalt was also off the charts, it was .038 mg% (mg per 100 g of hair) when the range is .000 - .005 mg%.
But I'm quite sure that the source is external, I'm using a shampoo that contains seabuckthorn (Hippophae rhamnoides).
Seabuckthorn is high in B12 and thus high in cobalt.
Food Chem. 2017 Feb 1;216:301-8. doi: 10.1016/j.foodchem.2016.08.037. Epub 2016 Aug 16.
Isolation and analysis of vitamin B12 from plant samples.
Nakos M, Pepelanova I, Beutel S, Krings U, Berger RG, Scheper T.
https://www.ncbi.nlm.nih.gov/pubmed/27596424
Since the laboratories use mass spectrometry to analyze the hair you can only see the count of the atoms, not how they are arranged in molecules.
So even if it was from an internal B12 source it would be harmless, as rich and Fredd already pointed out.
I asked the laboratory (Trace Elements, Inc. Addison, TX) if they wash the samples (because of low sodium and potassium values) and they don't wash it.