-ahem- At the end of Episode 2, Jolene said that as long as the St. Johns supply the Bandits with food, they would probably leave The Motor-Inn alone.
However; The St Johns were no longer able to give the bandits food. So obviously they would turn their attention to the Motor-Inn. Had Ben not provided them with drugs and other supplies, they probably would have stricken sooner. And the RV hadn't been ready until well...it actually happened. The casualty rate would be higher, if not everyone, if Ben hadn't supplied them.
And that shit about them having his friend? Ben made that up. In the heat of the moment the reason of keeping them off your backs didn't seem validated to him; so he made up something that made him seem like he had a more heartfelt reason.