Although there is also the good chance that simply touching the scope probe to the circuit would have made it start to run.

Absolutely right, Michael. Especially when he omitted burden capacitance, then probe capacitance will let the oscillator run, although circuit is misdesigned. By the way, touching oscillator quartz by hand will have the same effect: Stray capacitance introduced by hand touching simulates some burden capacitance, which might be enough to let oscillator start.

In such moments I miss the ability to have a quick look at PCB of poster. One second and we would know what's wrong, in most cases, right?

Bye,
Kai