It's way too early to say that. If the level of corrosion during the inspection was high enough to be a safety issue, the plane would not have been returned to service. And if there was something shady gong on, it wouldn't have been documented. It's possible that the excess corrosion was a symptom of a greater problem that caused this incident, but inspection engineers don't just say "oh yeah, this thing is falling apart" and sign it off. That would lead to certain jail time whether it causes an incident or not.