Putting numbers on the differenceDefault : It could be a payment miss but usually it is a non respect of one covenant.
S&P 36 years statistics show that One year Probability of default (PD) of C/Caa rated companies is 27%.
The one year PD of B3 companies is 7%.
It's a huge difference. Analyst knows that Bombardier was not a pure Caa rated company and that a new Rating was near but a confirmation by Moody's is a great news.