Don't Discount the Double Check

Today I was reminded of why you should always double check things.  I have been working with several other researchers on a Chromosome 20 puzzle .  We have 5 people who match along a given segment(with slight variations in the length) and who all match each other.    I had been waiting on my mother's results so that I could at least narrow down the lines over which I needed to search.  Those results came in Friday afternoon and late Saturday I ran a check on three of them against my Mom's results and neither matched.  This told me that the segment match was along my father's lines.  I noted this without writing it down and planned to email the researchers Sunday morning to let them know that we could narrow it down to Dad's lines.  Sunday morning came and I sat down to write the email and always one to double check...I checked again.  I input the numbers of the only kit that I hadn't run a one to one on with my Mom's kit....The only reason I had not ran this kit against hers was that this tester was a known closer cousin of one of the others and I thought that running just one was enough.  Was I ever puzzled when they had a match....Not on Chromosome 20...but on Chromosome 21.   It was a smaller match than the ones we were working on.  So I checked my notes and ran each of the remaining test against my Mom's.  None of them matched her accept this kit. I ran a One to One on mine and his and I had a match with him on Chromosome 21 also but it was smaller than the segment that he and Mom shared and that was why it was not showing in my Genome Mate.  So now, in addition to my Chromosome 20 puzzle...I have a Chromosome 21 puzzle.  One puzzle at a time....