When a corporation liquidates and distributes an asset on a non pro rata basis, will the entire realized loss be dissallowed, or just the portion that is distributed to a related party (i.e. >50%).

For example, suppose Corp X is owned by two shareholders.  A owns 70%, while B owns 30%.  If Corp X has a realized loss from one asset of (100K), and distributes the FMV of the asset on a 50/50 basis instead of pro rata, is the entire loss of (100K) dissallowed or just the (35K) which relates to the related party?