Were usually optimistic; most were 10-25% higher than any factory tune could hope to achieve. Though less common today, the over statement is still not unusual.
But this is only a non-rigorous analogy to the matter at hand...
I stand by my earlier statement that a 30m WR rating with case in good condition (without deformation or damage) and seals fresh and properly installed SHOULD be safe to swim with in a SANE private swimming pool (which usually maxes out at 30feet)
I have started reaching out to the industry; so far the results and replies are mixed, majority so far saying it is no problem.
TM