I wanted to show support to the engineers in the sense that I don't think you should encourage a working culture where you have "massive post-mortems" and expect people to feel bad for extended periods of time over simple mistakes. By not making a big deal out of it, you can also support your staff.
But I think our disagreement mainly stems from how we interpreted the parent comment. I thought it was very double, at one hand claiming to show support, at the other hand emphasizing how big of a catastrophy this was.
I just wanted to say that I think it most likely was a completely natural mistake, only exerbarated by the scale of the company, and that while you should take some action to prevent it in the future, you should not spend so much time dwelling on it. Shit happens, it's fine.