I am not sure that it would be a good idea to name the buyer of objects. This could lead to frustration and bullying when someone innocently finds a bargain and buys it before the intended shopper. If this is an issue within your alliance, then write to support at the time (within 3 days as reports are not kept longer than that) and they may be able to confirm or deny who it was. But they may not.
Market is one of the most frustrating and stressful aspects of the game. We have been asking for years for a change of some kind, but we have had no luck. Most of us are now resigned to the fact that buying and selling to alliance friends is down to luck and perfect timing.