A full-size SD card is a plastic shell around either a small circuit board or a sealed block. The shell cracks at the corners and along the edges, the contacts wear, the lock slider falls off, and the board or block inside carries on holding the data. The bench opens the shell and reads the board directly, or reads the block through its pads, and most cracked SD cards are the lower band. A card that has been bent has usually cracked the shell and sometimes the board; a cracked board is repaired at its tracks or its flash chips are read on a programmer.
A microSD is the block without the shell. Snapped across the middle, it has broken the package, the contacts and usually some of the test pads on the back, and the question is whether the silicon die inside, which is thinner than the card and nearly as wide, broke with it. If the crack runs through the package only, the die is whole and it reads through the surviving pads, with fine wires where the pads are gone. If the crack runs through the die, the circuits that store the data are themselves severed, and there is no laboratory process that reads a broken die. The bench can usually tell at the free look, under magnification, and tells you plainly, with nothing to pay. Send every piece, however small; a fragment with pads on it is the way in.
Water does two kinds of damage, and neither is immediate. Fresh water from a washing machine, a river or a glass does nothing to a card that is not powered; the harm comes when it dries and leaves minerals across the contacts and the pads, and when someone powers it wet and shorts it. Sea water is worse: the salt corrodes the contacts and the pads within hours and keeps corroding after it dries. The right response to both is the same: do not power the card, do not put it in rice, which does nothing a bag does not and leaves starch in the slot, and send it to be cleaned with the right solvents and read once dry. A card that went through the tumble dryer as well has had heat the card is rated for, and usually reads.
Heat and fire are the other end. A card in a car that burned, or a house, has had the plastic melt around a die that may be unharmed; flash memory keeps its data at temperatures that destroy the package, up to a point, and the bench reads the die through what pads it can clean. Pets and teeth are a kind of snapping, and the same rule applies: the die, whole or not.