The other issue is that Hamas released that death count less than thirty minutes after the explosion. There’s no way to get an accurate number that quickly.

A pretty plausible scenario is that they realized the fuck up, which probably did cause an extensive number of casualties given that the courtyard was apparently full of civilians, and immediately pushed a story about Israel catastrophically bombing a hospital in order to deflect attention, in hopes that western media would repeat the story without question, which was of course a correct assumption.