r! not working in any case ?

[Meino Christian Cramer]

Hi,

 from :h r! I read that 

                        r! <cmd> 

 can be used to transfer text given by a cmd via stdout
 into a buffer.

 I am using zsh 4.3.2 and have defined an alias of this form

                        alias hcnf='./configure --help'

 . I wanted to insert the expanded alias into a zsh-script, which
 I wanted to edit with vim.

 Therefore I did in vim (with the buffer containing the zsh-script):

                   :r! alias hcnf

 and got 

                    shell returned 1

                         Press ENTER to type command to continue
  
 . But 

                        alias hcnf

 and 

            alias hcnf | less

 given on the commandline to proof, that stdout is used (instead of
 stderr) works fine.

 I cannot find the error I did....

 Thank you very much in advance for any help ! :)

 Have a nice weekend!
 mcc