When I read "raid 5 rebuilt on local storage" the rest of your post was predictable 
IMHO the combination: local storage + VMFS + Raid5/6 should only be used to run VMs that have no important data so that a complete loss of the volume does not hurt.
I agree with Brian - use a ESXi LiveCD or a newly installed USB-ESXi-stick.
A ESXi that has never seen the volume in question has a significantly higher chance to be also willing to accept the volume as valid.
The option with the best chances in my experience is a Linux LiveCD with vmfs-fuse - if you only want to recover a single vmdk I would directly start with that approach.
Is the vmdk you need thick provisioned ? If yes - I can help you even when vmfs-fuse says "missing or bad magic number"