There is a 2 wire connector on the coil pack. If there is an aluminum oil pan on the engine, there is an oil level sensor. When this sensor completes a circuit, the ignition system shuts down. This is a common problem on all FWD V6 GM vehicles. For that reason, this is the first place I would check, since these wires are routed too close to the exhaust system from the factory, they melt and short out.
Keep in mind that this is only one possibility, but a common one.
Here is the list of things that will cause an engine to stall. Feel free to pass it along to the technician, there are so many possibilities that it is too easy to overlook some of them. This is a GENERAL list, applicable to all gasoline burning engines.
Incorrect idle speed.
Clogged fuel filter, or water/impurities in fuel system.
Ignition system components are damp or damaged.
Faulty emission system component, sensor, or wiring.
Faulty or incorrectly gapped spark plugs.
Faulty spark plug wires.
Vacuum leak at fuel pressure regulator, intake manifold, or hoses