HTTPS response for LB_FAILED event

I have written an iRule to generate an HTTP response when a pool is unavailable. In essence, it does

when LB_FAILED {

set message {Server [HTTP::host] is down}

HTTP::respond 500 content [subst $message]

}

This works for an HTTP Virtual Server. However, for an HTTPS Virtual Server (one that has an SSL Client Profile), the BIG-IP abruptly closes the connection instead of responding.

Is there any way to make this work with HTTPS? Am I doing something wrong, or is this a bug in BIG-IP? (I'm using BIG-IP 9.1.0 Build 6.2.)

For the complete iRule, see

http://devcentral.f5.com/wiki/default.aspx/iRules/Webserver_Down_Message.html