You can, wasn't the point I tried to make. I tried to point out the arbitrary expectations here. Depending on the fault such downtime can last a few hours to a few weeks. I don't think you can make conclusions on architecture in this case.

Perhaps it would be possible to roll back everything in just a few minutes but some users might lose a lot of work. If such special cases are to be resolved, it may take a lot of time. You just cannot really infer quality of architecture by downtime alone.