CEL turned off. Problem solved?
 

I was driving today and the CEL came on. First I retightened the gas cap.

After an hour later, the CEL turned off.

I thought once a CEL is tripped it stays on until you reset the ECU or by using an OBD reader to cancel the light.

Since the light turned off, can I conclude that infact it was caused by the gas cap?

Thanks.

Yes, until it comes back on the next time?

they stay on and check if the problem is still present, if its not present for X amount of key cycles/ X amount of checks then the MIL turns off.

The code should still be in the memory. Check with a reader what the code is.