In the Ariane 5 case, an ill-tuned and anyway unnecessary out-of-bounds check was compiled into the inertial platform firmware, causing a debug traceback to be dumped to the rocket gimbal controls, which interpreted the traceback as instructions to steer sideways. To be clear: without the trap, the payload would have been delivered unharmed. There was nothing useful that could be done about the out-of-bounds value during the actual launch, and they knew that when they built the system. Extra points for dumping debug details down a channel where it corrupted correct data.
Europeans I have mentioned this to considered what did happen a sensible outcome.
The code reuse in the project was pretty poor engineering, they reused code from a different project which had different flight paths and characteristics, and didn't test it.
The modern equivalent would be copying and pasting code from a completely different project, and then just shipping to production without testing it at all, even locally.
Note that Ada is being used for the Ariane 6.
Spacecraft failures that can be blamed on failings of a particular language are very rare. There was a planetary space probe that failed arguably because it was coded in Fortran.
Well, yeah. The firmware had been designed for a quite different rocket, the Ariane 4: https://www.bugsnag.com/blog/bug-day-ariane-5-disaster
I don't know how this is really a mark against Ada, it's an issue that would only be discovered by human intervention or by running a simulation of the rocket.
It is not a mark against Ada, particularly, it is a mark against brain-dead insistence on overflow traps.
And, destroying a $half-billion payload because you insisted on leaving debugging apparatus in a production system would seem less obviously correct if the cost of the loss were deducted from your salary. So, people insisting it was a good result may be interpreted as expressing satisfaction with freedom from consequences of irresponsible behavior.
Of course using straighjacket systems programming languages (as they put it) doesn't match hacker culture, so here we are.
