How was a pilot flagged as a security risk in 2024 still flying in 2026?

Flydubai FZ1073, Wednesday. The first officer attacked the captain mid-flight. Captain Smit Machchhar, an Indian pilot, fought him off while injured and got the cockpit door open so passengers could help. The plane landed at Tabuk. He is in hospital in the UAE. By every account he is the reason that flight landed at all. But the part I cannot get past: reports say the same person was suspended by Oman Air back in 2024 after being flagged as a security risk. Two years later he is in the right-hand seat of a 737. How does that happen? Airlines do not share these flags across borders, licences move between countries, and apparently a suspension at one carrier means nothing at the next one. Anyone here from aviation who can explain how pilot vetting actually works between airlines? Genuinely asking, because from outside it looks like there is no system at all.