"a poor model of the world, a logical inconsistency, or just a behavior which is confusing to users"
I expect when I pull from the queue (but it was designed non-atomically) that I will be guaranteed to only grab the item once and only once, even after a failure. That expectation is wrong, but the developer may have implemented their intent perfectly, they just didn't understand that there are error cases they didn't account for.
"a poor model of the world, a logical inconsistency, or just a behavior which is confusing to users" I expect when I pull from the queue (but it was designed non-atomically) that I will be guaranteed to only grab the item once and only once, even after a failure. That expectation is wrong, but the developer may have implemented their intent perfectly, they just didn't understand that there are error cases they didn't account for.