Why did Henry leap into the river to escape the Carabinieri?

The Carabinieri were questioning and killing officer, thus, Henry jumped into the river to escape them.

We stood in the rain and were taken out one at a time to be questioned and shot. So far they had shot every one they had questioned. The questioners had that beautiful detachment and devotion to stern justice of men dealing in death without being in any danger of it. They were questioning a full colonel of a line regiment. Three more officers had just been put in with us. “Where was his regiment?” I looked at the carabinieri. They were looking at the newcomers. The others were looking at the colonel. I ducked down, pushed between two men, and ran for the river, my head down. I tripped at the edge and went in with a splash.