Fuji NPH 400 - fogging and backing paper imprint caused by light?

I am *very* hesitant to suggest a backing paper problem.

Fuji NPH 400, 120 roll kept frozen for four years in it's factory wrapper. Defrosted for 12 hours before loading and taken on a trip. First 6 exposures were shot outdoors in cloudy conditions and are all fine. The last 6 have the backing paper symbols and numbers on them - but were shot at wide aperture and 1/10 second in a dim music club. Additionally on opening the camera, the film had not wound tightly to the spool so the final frames might have been affected. Camera used was a 1930s Zeiss-Ikon 6x6 folder which was last used successfully in June this year.

I've uploaded one of the good photos, and one of the bad for opinions. Is this just caused by the film not winding tightly enough to the take up spool? Did I do something else wrong?

You will note that the numbers are darker than their surroundings, not lighter.
Which generally implies a light leak that is partially shaded by the numbers, rather than the problems that appeared for a while on Kodak 120 film (lighter numbers, resulting from a chemical interaction between the ink and the emulsion).

THanks Matt...that's what I suspected but wanted a second opinion. Looks like the problem was the camera not winding the film tightly onto the take up spool. Then I believe it spent 5 days in lab before they got around to processing it due to repairing the mini lab. They did try to keep it out of the light but I appreciate there's only so much one can do.

Agulliver said:

THanks Matt...that's what I suspected but wanted a second opinion. Looks like the problem was the camera not winding the film tightly onto the take up spool.

Click to expand...

But then the artefact exposure cannot be explained by the figures shadowing the film