Occultist healed a highwayman for 28 and it wasn't a crit, how was that possible?

Highwayman has the gifted quirk which gives him 20% healing received, and only had damage trinkets on. So for the life of me I can't figure out how occultist could have healed for 28 when it should only range from 0-19, since I know for sure it wasn't a crit heal