Silver forever, HIE doesn't have an anti halation (AH) backing. If you load bulk HIE film in darkroom or dim light, the film will get light fog.
The reason is that as there is no AH layer, the light travels through the film from the ends and sides, this is called, "Piping". As in the light travels through the film, like light traveling through a pipe.
Personal experience from doing this myself as an experiment, was that the film gets so much fog that the pictures were useless for the whole roll.
In fact the film was taken out of the camera after it had been put in the camera originally in total darkness, exposed and then removed in the dim Ilford amber B&W safelight in my darkroom.
After about 5 minutes I realised that the roll sitting on the enlarger table was HIE. I quickly put it into total darkness, but the damage was done. This was a very good lesson (experiment).
Mick.