TIGHAR has already pronounced "Case closed" so RG doesn't seem to need any vindication from Ballard.

So if Ballard is a true TIGHAR believer, he'd save his time and diesel and stay tied to the quay.
I have a hunch this has more to do with producing a TV special and AE is a good "hook". Money has a way of making strange bedfellows.
TIGHARS "findings" on that out of the way island are circumstantial at best, certainly not enough to get anyone convicted of her murder if she was suspected of being buried there. The entire 'landing gear sticking out of water' thing is strange, it only makes sense if AE was going to land gear down...but why would she?
And if his interest is based solely on the blurry photo of the maybe...sorta...landing gear leg, I 'm not sure how much credit TIGHAR can claim since they did not take the photo. They may have publicized it, but I'm not sure if that elevated our safari suited friend to the level of Indiana Jones, let alone Howard Carter.
Stephan, I respect your opinion, but haven't you said in the past something along the lines of that RG is more of a charmer than scientist?
It's a shame that someone with Ballard's track record and reputation is getting mixed up with a group (and individuals) with TIGHAR's reputation.