Hey desert rat, not a pool specialist, but I've built/seen lots of nice pools up here in Canada on my clients homes. Without more info & better pics, it's hard to say... What does it look like under water ?? My first guess is that the waterproof substrate was installed incorrectly, resulting in the obvious penetration. Another possibility is no coats of sealer on any of the grout, or cracks in the glass tile or even the wrong grout being utilized by the contractor...(seen this last possibility personally) There are only a few specialized grouts for pools/underwater submersion. Also, depending on how the contractor finished the bottom edge of the tiling underwater, this would be my automatic start place to search for leaks. Once water has already penetrated under the tiling, it's just a matter of time till it all falls apart/off... probably bad news, rip out & reinstall properly... Good luck & let us know what transpired !