Yeah it really amused me that he went through tons of steps, buying lots of new hardware, etc before simply unchecking the delete images box.

You also shouldn't delete from the SD card using your laptop anyway. Always use the in-camera format. This was a bad workflow from the beginning, no idea why you would ever click "Delete after import" when importing directly off an SD card.

Also a good idea to copy to multiple locations when importing. When I do professional work and import into Lightroom from SD card I have it set to create two copies - import to my external SSD (the "working" copy) and also copies the files to my NAS (which is then backed up to the cloud).

Nowhere in that process do I ever delete anything.