itβs almost departure date. If he goes to immigration now, there certainly will be fines... However Thai lawyer claims that no overstay fine will be applicable when the said person shows up at the passport control in the airport. Claims that other clients of theirs left under the same conditions, and were pretty fine.
Strange that having very few cases and still forcing foreigners into quarantine on arrival, China is still quite reluctant on issuing new visas for potential visitors/expats.