An account beneficiary receives an HSA distribution as the result of a mistake of fact due to reasonable cause (e.g., the account beneficiary reasonably, but mistakenly, believed that an expense was a qualified medical expense and was reimbursed for that expense from the HSA). The account beneficiary then repays the mistaken distribution to the HSA. Is the mistaken distribution included in gross income and subject to the 10 percent additional tax or subject to the excise tax on excess contributions?