2 brothers killed in action

It would have been heartbreaking for a family to loose one son during WWI but for two sons to be killed in action would have been devastating.
I started researching 1412 Sinclair Sutherland after having received the Anzac Commemorative Medallion from Alan H. Sinclair served in 11th Battalion, he was wounded in action at Gallipoli on 13 Jun 1915. Then on 6 May 1917 he was killed in action. I noticed in the correspondence in his service file the name Francis' this was Sinclair's brother 5438 Francis Sutherland. Francis was killed in action on 20 August 1917.
In Sinclair's service record there are several letters from Sinclair's brother and sister claiming the Anzac Commemorative Medallion. How it was lost to the family is unknown. What is also a mystery is how it became partial buried in sand next to a footpath when it was recently found by Alan and his wife while walking their dog.
The returned medal tally is now 1870.