"Like almost all others that ... succeeded, it could have been avoided," said Bauer, who has written a book on French intelligence.
Did slip-ups help Radouane Lakdim, the French attacker, slip past security net? →
If it spreads to Europe, "it's simply a matter of time" before laptops are banned in the cabins of domestic U.S. flights, he said.
US prepares to ban laptops on flights from Europe →