Yes, if his 2018 household income was greater than or equal to 100% of the federal poverty level (but less than 401%), he would apparently qualify (or at least would not be disqualified for having insufficient income and having received no APTC).
Given that he estimated income of less than 100% of the federal poverty limit and actually had income of less than 100% of the federal poverty limit, it seems that his estimate was reasonably accurate.
If he had gambling winnings in 2018, they must be reported as miscellaneous income. Reporting gambling winnings not actually received would be fraud.
