I don't see (initially) any conflict here except for where the switch or manual control doesn't allow for state-independent operation (e.g.: manual slider for dimmer switch). In that case, I imagine upgrades being required in order to play nicely (e.g.: [1])
In the case where all controls for a resource allow state-independent operation, it's simply resolved with "last-in wins", and possibly more elaborate permissions models as automation adoption matures.
In the case where all controls for a resource allow state-independent operation, it's simply resolved with "last-in wins", and possibly more elaborate permissions models as automation adoption matures.
[1] http://www.amazon.com/Lutron-MAW603RH-WH-Electronics-Maestro...