I hate to say it, but this kind of thing happening with our strategic forces is hardly new. There is a book by a hardened anti-nuclear weapon activist named Eric Schloss that goes into a lot of similar incidences over the years. He's obviously got an anti-nuclear agenda so read the book with a grain of salt, but the stories he talks about are true and verifiable.
One such gem: At one point in time, we had a default signal that got broadcast out to all of the strategic warning centers to make sure the emergency alert systems were functioning normally. The test message was the exact same message that got sent out in event of a real nuclear emergency, with one difference. The "test" Message said the equivalent of the following:
000 Nuclear Weapons have been launched at us.
Unfortunately, due to a faulty computer chip on the sending end, one of these 0's computer errored and became a 2. Instead of the regular "test" message that was periodically sent saying "000 Nuclear weapons have been launched at us", a fault with a $.40c chip turned a 0 into a 2 and made it say this:
"200 Nuclear weapons have been launched at us."
Once the error was discovered and the cause of the fault detected, the "test" message was promptly changed afterwards.
This is one example of hundreds of similar incidences, some far more concerning then others, and most of them we don't hear about until decades after the fact. Who knows how many more are out there that have yet to be declassified.