It depends on the manufacturer I suspect, but for French engines you normally need maintenance checks after exceeding OEI continuous. Probably depends on the duration but I think if you used 30 secs of the 30 sec rating, it would be overhaul time.
This is why, for an intentional in-flight shutdown eg for a Chip, our pilots are encouraged to be careful to back the power off before shutting it down, so that the remaining engine doesn't run above OEI continuous. Otherwise you have 2 engines to change after landing, not just the one!