Strategy for Repair Database on SQL Server 2008 R2 Standard
Seems like you have a serious database corruption as CHECKDB points it out


  repair_allow_data_loss is the minimum repair level for the errors found by DBCC CHECKDB 


The only feasible options are :


Restore from backup or 
Repair with data loss => Might leave the database in a transactionally inconsistent state.


In both cases, you will have data loss (provided you have good full and T-log backups before that guy pushed green button instead of blue).

I would go for option 1 => Restore from a know latest good backup !

Refer to IAM pages, IAM chains, and allocation units and IAM page corruption examples


  UAT looks like as with success, no data missing


If you regularly have UAT in sync with PROD, best is to use that dataset to restore PROD - unless you are masking PROD data in UAT.