toerails CAN leak on any boat ! However, there is no CORE in that part of the glass. The deck & the hull both have a "flange" which is un-cored. Toerail leaks are much easier to see, therefore. You can just look & see. They are sometimes tough to access but there is probably no reason to go the epoxy overbore & fill route. Just rebed.
That doesn't mean that some bizarre leak couldn't make it's way clear into the bilge, but not likely.
