It doesn't follow automatically, but given the specific limit, one would assume that it was deliberately chosen and includes an error margin. There's nothing wrong with flying at their assigned altitude, which was above the limit.
In aviation, you have to manage risks, you cannot avoid them entirely. For example, there are different levels of redundancy, depending on how critical a system is. There may be two, three or maybe four units, but there surely aren't 25 units of even the most critical equipment - the plane would be too heavy to take off. At some point, you have to decide what the acceptable risk is, and go with that. I think your argument has a strong hindsight bias.
In aviation, you have to manage risks, you cannot avoid them entirely. For example, there are different levels of redundancy, depending on how critical a system is. There may be two, three or maybe four units, but there surely aren't 25 units of even the most critical equipment - the plane would be too heavy to take off. At some point, you have to decide what the acceptable risk is, and go with that. I think your argument has a strong hindsight bias.