I'm having the same issue. Based on some reasearch, I read that the hatch lock is controlled by the actuator on the passenger side door. So in this case since the passenger door lock actuator is acting up, the rear hatch is also being affected. In my case, I have to manually unlocke the front passenger door in order for the rear hatch to open. It works about 99% of the time this way. The other 1%, when it happens, even by me unlocking the front passenger side door the rear hatch doesn't want to open.
This has been going on for sometime now. I wanna say almost a year maybe. Hopefully someone can post a solution to this as it is very annoying and also a safety concern I think.
2005 Murano S_Black_2WD
Repairs to Date (all done myself): Lower Control Arms, Front Right Axle Half Shaft, High Pressure Power Steering Hose, Oil Pan, Front & Side Motor Mounts, Coolant Drain/Refill, Drive Belts, Front Struts, Oil Cooler Gasket, Camshaft Position Sensors, Rear Shocks
Repairs Coming Soon: Spark Plugs, Valve Cover (if leaking oil).