I think anytime a hide glue has any kind of an offensive rotten type smell I would'nt use it.Meaning it has lost it's strength.Dark hide glue I won't use either.Should be a lighter slightly amberish or golden type color when dried.
I'll relate that to brain tan hide finishing.Not fleshing soon enough before dried or not freezing it soon enough the fat burns or breaks down the integrity of the gelatin in the fibers and weakens them so that during the roping process the fibers come apart and a hole will appear.