From one reactive intermediate, two products compete: each is reached over its own transition state. The rate of each path depends on its barrier — Eyring's k ∝ e−ΔG‡/RT — while the stability of each product depends on how deep its well sits.
Run cold and stop early and the lower barrier wins: this is the kinetic product, even if it is the shallower, less stable well. Heat the flask and wait, and the reverse reactions wake up; the system drains into the deepest well — the thermodynamic product. The two can be entirely different molecules.
The Curtin-Hammett principle is the sharp edge of this: when the products come from rapidly interconverting intermediates, the ratio is fixed by the difference in the two transition-state energies, not by how much of each intermediate exists. Set the barriers equal and the kinetic ratio is 50:50 — no matter what the wells do.
The simulation stopped unexpectedly — the lesson continues without it. You can move on; nothing you did was wrong.