ASM_RESPONSE_VIOLATION SECTION doesnt see ASM violation

The key word here is RESPONSE. If you have a REQUEST with HTTP method DELETE then there is no ASM_RESPONSE_VIOLATION because the request never gets to the server, so there is no response and no response violation. and the reason why your request never gets to the server (pool member) is because the second F5 ASM sees the DELETE in the REQUEST it blocks it.

You should be using ASM_REQUEST_DONE if you want to catch the "Invalid Method" violation which is raised when DELETE method is blocked in the F5 ASM policy