I find this example ironic. Car accidents got the term "accident" for a reason. There are many accidents where the person in question thought they were doing it right only to miss something and end up in the hospital e.g tire low on air, some engine part failing, brake failed in unexpected weather conditions etc. It's similar to the cloud in that respect. You think you got it right only to have some unexpected spike in traffic or some other event trigger weaknesses in the setup and end up costing you