Any idea how this happened? It's beyond unusual for files to simply disappear. Was anything accidentally moved to the trash and then restored? If you're sure of what you're seeing the Sony Media Services group may be able to help, but if there are no .mp4s the prognosis is not good.. I'd call the US tech support group first to make sure nothing else can be done-- 800 883 6817. If you want to post some screenshots of what you're seeing in Finder vs what you're seeing in your recovery software I may be able to offer more suggestions..
Ran into this very problem today, first time i've ever seen it in nearly 3yr's of using the camera. should have been at least two clips from a take but after ejecting the card and putting it in the mac nothing appeared apart from the clips that were already on there.
Is it worth taking in for a service? I was lucky in that this was a tv pilot and was able to spot the shot was awol and repeat the shot straight away but a lot of the work i do is weddings which could have a significantly worse result.
I sent my card off to Sony in the end and there was nothing they could do to save the clip. I'm still very confused by this problem. I'm just hoping it never happens again. Sorry I cant give any better news.