A properly done shotcrete pool that is done with the proper application of shotcrete and proper strength of shotcrete should be water tight. If you have holes that are leaking water through the negative side of the pool you have an issue. If the leaks are coming around areas that you had a penetration like the plumbing lines or lights than the penetrations were not sealed up properly. If they are coming through in the walls or floor you have a a issue with the application of the shotcrete. Plaster is not a water proofer. All concrete is permeable to water unless you take steps to make sure to block the water from going through it.