Yes, the distributor and the cam has to be in time. The cam and distributor are timed together by the distributor gear, and taking the timing belt off won't change the timing between the distributor and cam. The only way that would happen would be if the distributor were physically removed from the engine. Then, you'd have to put the timing belt on, line up all the marks, then install the distributor.

But still, the distributor would have to go back in pointing to the #1 cylinder spark plug wire with that cam lined up with the timing marks. It would just be more insurance to have the timing belt on at that point in time.

And again, all this would only be necessary (retiming the distributor) if the distributor was physically removed from the engine.

As it sits now, just lining up the timing marks and putting a t-belt on would allow the engine to start and run.

Maybe you're thinking that the distributor turns at a different speed than the cam. But the distributor makes one full rotation for every one full rotation of the cam. If the cam's timing mark is lined up, then the distributor will be in the same place every time as well and won't need to be changed or even adjusted.

Now after he puts on a new belt, gets the engine warmed up and such, then he should recheck his timing. Especially if he ever had the engine tuned with a worn belt. The new belt will bring it all back together nicely, and most likely, will change his ignition timing by a couple of degrees. But then again, if the timing was never changed from the factory, then it will all go back to what it was before.