We can also say, without hesitation, that Bali while throwing Sugrive out of the Kishkindha kingdom, did tell Sugrive of the forest dwellers rule, that if Sugrive wanted his wife and children back, let Sugrive challenge him in a man to man combat and defeat Bali. Such rules do exist in the nascent, growing societies, and existed in North America till as recently as 300 years back.
Rest, of course, is history. Now the big question? Why a Prince, a King, a Kshatriya, broke the existing Maryada by INTERFERING DECISIVELY in a man to man combat? Such things are unpardonable even today.