iRule Switch with no default action and no default pool

Hello,

I'm using switch command in my irule and choosing pool based on the HTTP path. Please note I haven't specified 'default' pool neither on the virtual itself nor in the switch statement.

What is the expected behavior when the HTTP patch doesn't match any pattern in the switch statement? According to this article https://devcentral.f5.com/s/articles/irules-101-04-switch the switch returns empty string. But what is expected behavior then?

What I am observing is that some irrelevant pool is being selected. This pool is NOT mentioned anywhere in the irule. I would expect a reset because of no match but that's not what is happening. Please note there's no persistence configured and I tested this by initiating new TCP connection. This pool should never be selected as it's not even remotely related to this config.

It seems there's some implicit pool selection but I can't make sense of it

Seems someone asked this question but no answer https://devcentral.f5.com/s/question/0D51T00006i7N5ZSAU/irule-switch-default-action

Any ideas?