IANANAL (I am not ANAL), nor am I a lawyer, but it seems to me the cashed check and the 83b form (especially if filed with the IRS) both pretty-well corroborate

IANANAL (I am not ANAL), nor am I a lawyer, but it seems to me the cashed check and the 83b form (especially if filed with the IRS) both pretty-well corroborate the fact that money was exchanged, and it was for stock options.