It wasn't immediately clear to me from the documentation (or the code) what the boolean argument to this function was for. It took some additional reading of the code to figure it out.

1. Can we document what the boolean is for in this `@param` comment here?
2. Should we switch the polarity of the boolean? Given that it's a single callback (which reads to me like "success callback"), I was surprised that `true` signified a timeout. Should `true` signify success in loading the script, and `false` signify a timeout instead?