I had the same problem during purchase of our boat last year but the Lab here ( Wear Check ) could not determine the amount of glycol in the oil. I was told that because the way glycol mixes / interacts with oil, it is impossible to determine how much glycol is present, they can only determine Yes or No for glycol. To explain ...... their ( the lab's ) baseline was .06 ( whatever that means ) ... so @ .0599 or less is NO and @ .061 and more is Yes. Could be a contaminated sample, oil cooler leak, or on the outside ... a head gasket ... ? so I was told. In my case, I wrote it off as a non - issue at this time, as I am not losing coolant, not gaining oil, there is nothing coming out of the exhaust etc. and there is no visible contamination of oil or coolant.
Good luck with this one .... FB