Hi S,
see the comments section of S-Record Generation with gcc for ARM/Kinetis | MCU on Eclipse which lists way to have a .s19 extension instead.
The point is that this CodeWarrior plugin always generates a file with .hex extension, regardless of the format.
So you can rename that *.hex to *.s19, or simply verify this with opening the file with a text editor.
Erich
PS: there is another post explaining the different formats: S-Record, Intel Hex and Binary Files | MCU on Eclipse