Where does this iRule end?

some curly brackets are missing. The Correct version of the iRule is below. This iRule always executes LB::detach command, after that, does the second switch command where it hits.

when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::uri]] {
     "*/aaa/*" {
        if { [active_members Pool_aaa] > 0 } {
        else {
           pool Pool_sorry
        }
      }
     }
     "*/bbb/*" {
        if { [active_members Pool_bbb] > 0 } {
        else {
           pool Pool_sorry
        }
     }
  }
  }
  LB::detach
  switch -glob [string tolower [HTTP::uri]] {
     "*/ccc/*" {
        if { [active_members Pool_ccc] > 0 } {
           if { [HTTP::cookie exists "CCC"] } {
              persist uie [HTTP::cookie "CCC"]
              pool Pool_ccc
           }
           else {
              pool Pool_ccc
           }
        }
        else {
           pool Pool_sorry
        }
     }
     default {
        if { [active_members Pool_default] > 0 } {
           pool Pool_default
        }
        else {
           pool Pool_sorry
        }
     }
 }
 }

I would say that it ends here

when HTTP_REQUEST {
  switch -glob [string tolower [HTTP::uri]] {
     "*/aaa/*" {
        if { [active_members Pool_aaa] > 0 } {
            pool Pool_aaa
            log local0. "Directing to pool_aaa"
        } else {
           pool Pool_sorry
           log local0. "Directing to pool_sorry"
        }
      }

Though you can always add a logging command to your code and see which statement is hit