The are three main reasons I get here on problems with warped brake discs!

1)Cold water reaching a very hot disc!Breaking very hard in the rain or washing the car when the discs are hot.

2)Incorrect disk installation!Sometimes mechanics take discs off and just put the new ones straight on,when they should clean/polish the wheel hub surface before putting new disc in!THIS OBVIOUSLY DOESNT APPLY IN YOUR FIRST CASE since the discs were new!

3)warped wheel hubs!We get a lot of problems on HONDAS !In this case its not the discs that are warped!

During the years, I havent got many cases here of pads damaging the discs!