Rip John C. Dvorak, writer of the Abort/Retry/Fail column from PC Magazine.
On a different note, never underestimate the value of a modal dialog that gives you a chance to retry an IO operation that failed. Loose USB cables and network shares over Wifi can make those happen a lot more often.
Keeping one of the disks from the pile was peak bff/sibling rivalry antics. It's like keeping out one of the pieces of the puzzle so nobody can finish it but you.