Looking on the 463rd.BG site on
http://www.463rd.org/1945missions.htm it shows no losses and no claims for many missions which looks like the Moosbierbaun raid was probaly unopposed. The results are also shown as not observed which suggests poor weather over the target which seems comfirmed by other bombadiers having problems. In these circumstances it is likely that if the Luftwaffe had any fighters available their operations might have been curtailed. Looks like the clients father done really well with his bombing.