PEX PIPING IS NOT Leak Resistant
PEX is becoming more and more popular for pipe installations. It's lack of required fittings and flexible nature allow for quicker installs than traditional rigid pipe systems.
This seemingly quick and flexible installation does have its downfalls. There is a minimum allowable bend radius for PEX pipe and occasionally an installer will exceed the allowed bend radius and sometimes may even kink the pipe.
Extreme bends and kinks place a very high local stress on the wall of the pipe making the pipe susceptible oxidative degradation. This is especially true in southern climates where the chlorine levels run high.
This PEX pipe was bent beyond its limit and developed a leak at the stress point.