I’d be inclined to agree with you. I’ve not read anything that would suggest that a failed pelican/puffin crossing effectively becomes a Zebra. The ZPPPC Regs state that when a red or amber signal is showing, drivers are to stop. As I see it, it’s the signal that gives the stopline its legal status.
The same argument applies at a junction with ped facilities. When a ped phase is inhibited due to two red fails on a conflicting vehicle phase, the responsibility is clearly on the pedestrian. A bit different admittedly, because the pedestrian sees a constant red man rather than nothing at all, but same principle surely!