France has very good outcomes for angioplasty. If it was left main I doubt he would've made it to surgery. The fact he's had Cabg would in indicate medium sized vessels, some with full occlusions involved.
Loads of people have Bypass with left main stem occlusions, it could have been a transient blockage or clot. No point speculating anyhow unless someone shows me the angiogram then I can tell you what was up
Just glad he is fine