Which is really a positive thing. The idea of a star exploding in supernova and destroying a planet, then being neutralized as a threat by creating a black hole, is physically and dramatically extremely challenging, and it's clear the writers (of the movie or the comic) never paid much thought to how it would work out. The more ambiguity we have, the less of this half-hearted "intent" we have to take into account, the more chance there is of dreaming up something that would be even halfway plausible, physically and dramatically.
The one thing that is useful for all models of explanation and apology is placing all the action in the smallest possible volume of space. This helps with making the supernova destructive despite the destruction supposedly moving at a slow pace; it helps with Spock being in a hurry despite flying a fast ship; it helps with Nero being a threat despite flying a slow ship; and it helps with our heroes being the only ones capable of responding in time despite them flying ships that are not faster than the Starfleet average.
This is the main incentive for putting the Klingons in or near the RNZ, both in the teaser and just after Nero meets with Spock. If they were at any significant distance, Nero wouldn't get to Vulcan in time, not in a ship that fails to get from Vulcan to Earth before our heroes despite the heroes making detours and being limited to warp four.