My brother went to Walgreen's and bought a DNA test in a box, swabbed all parties and put all the swabs in the same envelope and they were all touching one another. The results came back and one was in the 92 percentile and the other was in the 96 percentile. Is there a possibility that the swabs were contaminated with his DNA when they touched in the envelope? Does he need to take this DNA test the right way through a reputable company?