GnuTLS continuing after rejecting certificate?

henk on irc writes:

02:00 <      henk> Hi, #mst-374: I’m running mutt 1.10.1-2.1 on debian stable 
                   and use it to connect to an ssl-enabled imap-server. One of 
                   the certificates in the certificate-chain the server sends 
                   is expired and mutt displays "WARNING: Server certificate 
                   has expired" and gives me the options "(r)eject, accept 
                   (o)nce". When I press 'r', it still continues to connect 
                   and asks for my password. The behaviour is exactly the same
02:00 <      henk> when I press 'o'. I would have expected it to stop 
                   connecting when I press 'r'. Does anyone know the rationale 
                   behind that? It feels like a bug to me but maybe I miss 
                   something.