[Leica] Film broken in half on Leica IIF?

[Matej Novak <matej.novak@hermes.si>]

Hello,

 Yesterday I took a roll of PAN 400 to the local store to have it
developped.

 A few hours later I came back to the store, and they showed me the roll
that I brought and two stripes of film coming out of it. They said that when
they used a special tool to get the film leader out of the roll, this is
what came out. They have also demonstrated me how they do it on another roll
of film that somebody just brought it, and it worked without problems. Then
we kept pulling the film out of the roll, and it seems to be broken all the
way. 

 I'm using a Leica IIF, and I'm wondering what could have caused this (so
that I know what to avoid in the future):
- - did I trim the film leader uncorrectly
- - is there a problem with the film advance mechanism of my Leica
- - did the local store somehow broke the film when they tried to get the film
leader out of the roll with their special tool, and as we kept pulling the
film out of the roll, the film kept breaking?
- - something else?

 Did somebody on the LUG had a similar experience? 

 Please advise.

Thanks,
Matej