HSL for https redirects

Hello (DevCentral) world!

I'm running 11.5.1 and I'm trying to use HSL to log whenever the _sys_https_redirect irule does a redirect.

when HTTP_REQUEST {
       HTTP::redirect https://[getfield [HTTP::host] ":" 1][HTTP::uri]
    }

I pulled this HSL irule off of devcentral. I added logging to see where it was failing and from the logs I can see that the CLIENT_ACCEPTED and the HTTP_REQUEST portions of the irule are triggered but not the HTTP_RESPONSE. Any ideas why?

 iRule Source for remote logging using HSL
 From: W3C Extended Log File Examples (IIS 6.0)
 http://www.microsoft.com/technet/prodtechnol/WindowsServer2003/Library/IIS/ffdd7079-47be-4277-921f-7a3a6e610dcb.mspx?mfr=true
Fields: date time c-ip cs-username s-ip cs-method cs-uri-stem cs-uri-query sc-status sc-bytes cs-bytes time-taken cs-version cs(User-Agent) cs(Cookie) cs(Referrer) 
when CLIENT_ACCEPTED {
 
   Open a new high speed logging connection to the syslog pool named syslog_server_pool
  set hsl [HSL::open -proto UDP -pool test.syslog.pool]
        log local0. "client_accepted hit"
}
when HTTP_REQUEST priority 999 {
  Save request variables that are not accessible in HTTP_RESPONSE, like the URI, request method, etc
    set req_start [clock clicks -milliseconds]
  set cs_username [HTTP::username]
    set cs_uri_stem [HTTP::path]
    set cs_uri_query [HTTP::query]
  set cs_bytes [HTTP::header Content-Length]
  set ua [HTTP::header User-Agent]
    set cookies [HTTP::header values Cookie]
    set referer [HTTP::header Referer]
        log local0. "http_request hit"
}
when HTTP_RESPONSE {
 
   Send the syslog message with a syslog facility of 134 (local0.info)
    See the HSL wiki page for details on the facilties:
    https://devcentral.f5.com/wiki/iRules.HSL__send.ashx
  
    Replace null values with a hyphen:
       Use string map to replace a "tab space tab" with "tab hyphen tab"
        log local0. "http_response hit"
    HSL::send $hsl "[string map [list "\t \t" "\t-\t"]\
     "<134>\t\
       [info hostname]\t\
      [IP::local_addr]\t\
     [clock format [clock seconds] -format "%d/%m/%Y %H:%M:%S %z"]\t\
        [IP::client_addr]\t\
        $cs_username\t\
     [clientside {IP::local_addr}]\t\
        $cs_uri_stem\t\
     $cs_uri_query\t\
        [HTTP::status]\t\
       [HTTP::header Content-Length]\t\
        [expr {[clock clicks -milliseconds] - $req_start}]\t\
       [HTTP::version]\t\
      \"$ua\"\t\
      $cookies\t\
     $referer\
       "]\n"
}