No. Both the "safe" and "unsafe" versions are asynchronous. The safe version waits for a response from the server before invoking a callback. The unsafe version does not, but that doesn't make it synchronous -- the operation is still potentially executing on the server when the function returns.

This completely misses the point! I am talking about what the API does which is what you are using. Whether it internally makes one over the wire call or 10 is irrelevant. With the parameter set one way, the API does not return until the server has completed the operation, and the other way the operation could still be in progress or could have errored - you have to explicitly ask.

My contention is that "safe" is a bad name for the parameter, and "async" is far better suited as it describes the semantics of the API.