Oil light

You bounced around everything except the actual cause. The "oil" warning light turns on due to low oil pressure. The light does not turn on in response to low oil level or leaks, although those can lead to low pressure. Given the age and relatively low mileage, a defective pressure sensor is more likely than an expensive engine problem. Oil pressure will drop too if engine speed drops too low. If you only saw the light when something caused the engine speed to drop, the light turning on can be expected, and that does not point to an engine oil system problem.