I'm thinking the memory card was part of the INternal circuitry which was partially protected by the outer shell/casing of the camera which might have been protruding making it more susceptible to heat.
Spectacular pictures reminding us that nature rules and/or does what ever it wants to when it wants to. The river of lava going away from the volcano caught my eye along with the height of lava bubbling.
It sounds like a little "robot" thingy (the drone) so it goes in as close as it can get, and it must have survived and came back with the outside of the camera melted. That's all I can figure
that's one thing I would not want to get up-close-and-personal with I've always had a fear of fire anyway, and seen too many movies when I was a kid of "beautiful virgins" being sacrificed to the gods I guess, like Bird of Paradise? Remember that one with Debra Paget and Jeff Chandler.