That is to say, if something happened — and I've never seen anything like this happen, but I've only been looking for 20 years — if something happened, they might all come out if they were needed.
Es decir, si algo fuera a ocurrir — y jamás he visto algo así ocurrir, pero solo he buscado durante 20 años — si algo ocurriese, todas podrían salir si fuese necesario.