Nobody is questioning his aeronautics skills - he may have done well, he may not have. Considering he didn't go into that field and choose to do adventure tourism in space or research in space, I'm betting he couldn't hack it in that field either. But we don't have anything to go on because he chose not to showcase those skills.

What he did choose to showcase was his ability to translate those skills to the ocean environment - which he failed at, significantly (ie, not smart). And when experts in the field offered their sincere advice, he showed arrogance, a classic sign of "not smart". His own team tried to recommend different tests and different materials and he fired them instead of listening to them, not smart.

He had every opportunity to make smart decisions. People who are specialists and are very smart definitely work on projects in other fields, but they know they are specialists and know when they've hit their limit of translating their skill set and when to take the advice of others. Yes, there is a difference between smart and wise, but this guy was not smart.