Yes, this sounds plausible. Maybe the airline did know about the missing bolts and didn't want publicly admit it. If they didn't notice the bolts missing it's

Yes, this sounds plausible. Maybe the airline did know about the missing bolts and didn't want publicly admit it. If they didn't notice the bolts missing it's a completely different story. If 4 bolts get loose, maybe 50 more go loose soon after. It's not impossible that all of them were not mounted correctly and the first 4 were only the beginning.