It shall be a Class 2 misdemeanor for any such beneficial owner, director, or officer, directly or indirectly, to sell any equity security of such company if the person selling the security or his principal:
but no person shall be deemed to have violated this section if he proves that notwithstanding the exercise of good faith he was unable to make such delivery or deposit within such time, or that to do so would cause undue inconvenience or expense.
SDCL 58-5-70