Even if you mistakenly remove the SD card or turn off the power while data is being written to it, all of the saved data will be retrieved to ensure that you don't lose it.
It is about probability and it is extremely unlikely that pulling the card during a write damaged it
I know he didn't damage it by pulling it out of the socket.
I can only assume that your time in academia robbed you of some vital fault finding ability. Something happened, I have never known any academic so starved of data that he will not formulate a hypothesis, so what is yours?All you keep saying is it could not be this. No alternative explanation?
Static on a signal pin could do it.
Do not touch the terminals with your hands or metal objects. The card may get corrupted or erased by electrical noise, static electricity.
To avoid losing stored data, keep SD memory cards away from static electricity or electrical noise that may interfere with the card. When carrying SD memory cards, be sure to put them in their case to avoid static electricity damage.
uint16_t const SD_INIT_TIMEOUT = 2000;