Saturation would have been fine; actually anything would have been fine, since the result was not actually used in flight. However, Ada traps, and the trap was

Saturation would have been fine; actually anything would have been fine, since the result was not actually used in flight. However, Ada traps, and the trap was not handled (because resources were tight and overflow was physically impossible on the Ariane 4, for which the code had been written), and the specification required that the system shut down entirely on an unhandled trap.