I believe I do have a timeline of events that you might find elucidative.
On the beach, Alex asks Russ about a little mark on his shoulder. Russ tells him that it is a tattoo of the lower jawbone of a crocodile.
He explains that a crocodile has strong muscles for closing its jaw but only weak ones for opening it. He claims that the tattoo is to remind him that strength depends on how you measure it.