Tanya,
Try some of the links on my Rohatyn site for researching Galician soldiers in the Austro-Hungarian Army.
https://sites.google.com/site/rohatynshtetl/home/research/ww1-soldiers
There are various resources for research.  If he was injured or taken hostage as a POW, you might find his name in the lists.
If you are up for the search, he may be among the many microfilms of Galician Military records that are available to view on the FamilySearch website

Alex Feller
Chicago, IL
rohatynshtetl@...