If you think about it, the default iOS guidelines somewhat reflects Jef Raskin's idea about zooming interfaces:
As you work your way deeper into the navigation hierarchy transition animations will slide you towards right and if you move back they will slide you to the left. If there is some sort of contextual popover it will always slide in from the bottom.
Even though we are not navigating a canvas as explicitly as we are in for instance Prezi, that's still what we are doing and the consistent slide-animations provides a subtle way to give the user cues about where in your app he is.
If you ad an off-canvas menu and a hamburger icon to that pattern, the idea is that the menu must be the first level of navigation and from there on you drill down in the hierarchy by moving to the right.
For this reason I would argue that you should replace the hamburger icon with a back-button whenever you are on subpages, as to not ruin the conception of this "virtual world" you are navigating. This is actually the way Facebook worked "pre iOS7". In addition Facebook allowed you to get directly from a subpage to the menu by swiping from the left, but I don't think a lot of people knew about that.
If you have a deep navigation hierarchy, however, this might not work as the user might end up having to press back > back > menu too often. In that case you might have to stick to the hamburger and then either skip the back button altogether or maybe provide it within the menu.
As for Android you should not provide a back-button in-app, as it is already available on the phone, either as a real or a soft-button.
