How so? Mohammed told his pal to wake everyone up for pre-dawn prayer, the guy fell asleep instead, and everybody (Mohammed included) overslept. They performed the prayer after dawn instead.
What you implied in your post was that this was something that happened regularly; it was not. Furthermore, read the name of the chapter of the Hadith you cited, the goal of citing this Hadith is to denote prayer times.
By the way, don't be surprised at the existence of green in Arabia. There is an authentic Hadith (in Muslim's collection) that states that the Hour shall not come until Arabia returns into being rivers and meadows.
Lastly, the Companions of the Prophet Mohammad (Peace be upon him) are called that, not "pals".
It is often argued that the Prophet's inadequate actions would form part of a teachable moment. So in this case, it shows the importance of making promises you can keep, having failsafe measures etc., that Bilal could have done.
Or am I misinterpreting this?