This is what they got from their witnesses. Via TPM
One of the voters was Douglas Thompson, who admitted under oath that his girlfriend filled out his absentee ballot application for him, signing his name with her own hand and purporting to be himself. His ballot was rejected because the signature on his ballot envelope (his own) did not match the signature on the application (his girlfriend's). The Coleman team's argument appears to be that he is still a legal voter in Minnesota, as the signature on the ballot was his own, even if admitted dishonesty was involved in getting the ballot.
It was so bad that over at Dailykos, some theorize that Coleman is throwing the case so that they can claim the race was stolen from him by Franken. Making Franken the boogeyman as to drum up donations.
Not a bad conjecture. At the end of the day, Franken is still going to win.