HiCustomer welcome to Just Answer!.
You may have nailed it, Calboy! If your engine quits suddenly, with no gradual softening of performance... like the key was turned off, you probably have an electrical situation. The cam sensor is over-represented in these type of issues on the 2.7 engine.
While most instances of cam sensor failure would cause a code to set (P0340, P0344), a situation where either the cam or crank sensor shorts the 9v power feed that's shared between the two to ground can take both sensors out. With no cam OR crank signal present, the PCM won't set a code for either because it doesn't know whether the engine is turning or not. No reference signal from either source will do that.
One thing you could try if you get stuck again is to disconnect the cam sensor altogether. The engine controller (PCM) can operate the fuel/ ignition system using just the crank signal in this year, but it takes a little more cranking time to get it lit... around 5-7 seconds of continuous starter grinding. While the engine will run without a cam signal, it doesn't like an erratic or disappearing signal while driving. It needs to see NO signal during cranking to switch to Plan B... no cam signal.
Running-wise... it's going to feel very similar to normal when running on the crank sensor alone. Your rev limiter will be lowered a bit and the trans might shift just a bit funny... but if it keeps running or restarts sooner after disconnecting the cam sensor, you'll probably have your answer.
Be advised that an actual short to ground of the 9v power feed to cam/ crank will result in a delay in restarting the engine. You'll need to leave the key OFF for close to a full minute while it regroups.
I do have some good news. The cam sensor has dropped in price to right around $25 now and it works better than the original unit if you decide to just go with a hunch. Replacement is pretty easy, requiring removal of a single 13mm hex-head bolt (with protruding stud) on the left cylinder head pointing straight forward. You'll find the cam sensor just below a section of harness loom that stretches across the front of the engine. The 3-wire connector uses a red slide-lock tab that must be repositioned to the opposite position before the thumb-pressure release tab will allow disconnection.
Write back if you have any questions or if you'd like to talk about it a bit more.