One hack news site posts something and everyone runs with it without checking anything.
The photos have names attached. They have photos and videos posted by those very people to their own social media.
I will say they don't have any evidence that the photographers, let alone the media orgs that hired them, knew about it in advance, or that they entered Israel at the start of the attack before the civilians joined in.
But after honest reporting published their report, other Israeli reporters dug up pictures tying at least one of the photographers to Sinwar himself. Doesn't get any higher up in Hamas.