Yet another accident

[JW PHOTO]

that's almost never the case with this sort of problem.
it is quite incredibly rare to find a film - even from a minor manufacturer - with such a gross fault.

it will be user error of some sort

I do agree pdeeh and think the OP's title for his post says "accident", which probably did happen somewhere on his end. I sure know they happen on my end. Of course the ones on my end are usually "stupid accidents".

 

[Fraunhofer]

I am not saying this is not a stupidity on my side, but most stupid things I do are obviously stupid (that is in hindsight).

Here, I just can't figure out where I screwed up and I am pretty sure that somewhere along the way I did...

 

[pdeeh]

yep sometimes sh!t happens and we can't easily work out what it was that went wrong.

 

[AgX]

The only user accident I can think of would be opening the loaded drum again in daylight. Likely to prepare it for the second film, not realizing on opening that there is one film inserted in already.

Though it is hard for me to imagine that such error would not be detected after opening.
At least when inserting the second reel the existance of a first reel inside the drum should be realized.
If not, it would mean that two errors happened in succession.