Dave,
I ran warranty repair centers for several non-pool related manufactures for about 30 years.. "One" failure does not make any kind of trend. None of these manufactures had a full time root cause analysis team. The repair center was usually the "Canary in the coal mine". As items came back for repair or replacement we would enter the failure info into a database and then produced reports showing failure rates and failure trends. Only if a trend was indicated did the alarm go up to get engineering involved.
I suspect that when customer service enters an order for a free replacement part, all the relevant info is automatically added to their failure database.
The customer service guy is just trying to make the customer happy and shipping things back is not what most customers want to do.. My guess is that the majority of reported "failures" are either caused by the user, or not really failures at all, so it makes zero sense for everything to be returned. You would be amazed at what I have seen returned as "warranty" failures.
As far as I can tell, this is the first time this type of failure has been reported here at TFP.
Thanks,
Jim R.