Hmmm, that is a tough one to swallow. I would have liked to read the entire article and to see the actual results of the tracking.
I wonder whether the full article gives reference to the method f navigation.
From the abstract is seems quite conclusive; if the pythons never veered further than 22 degrees from their required bearing, that would mean that they always stayed within a 44 (lets say 45) degree "slice" of the compass, which is 1/8 of the 360 degree circle. That's quite something! It's obviously that they were aiming to go somewhere.
Here's just a cr@p graphic I quickly made in Paint showing how accurate they really were. The snakes remained in the green slice 100% of the time, which is quite something.
"I am dying by inches from not having anybody to talk to about insects." - Charles Darwin