OK.
I checked for a rough guesstimate HERE to see how far Diego Garcia was from Kabul.
We get 2888 miles (2510 nautical miles).
Now, given that the BUFF is subsonic, at a good clip she'll cruise at 600 MPH.
Do the math folks. From alert time (I am going to give them credit for having fully loaded BUFFs on a Ready-5 alert status) to take-off to refuel to target acquire is still over 4 hours (Closer to 5 by my best guestimate)...and that's just to Kabul. Since I have no idea how far Camp Tilman is from Kabul, I'm just going to use the Kabul locale to frame my point!
So the attack continued for enough time for BUFFs to get from Diego Garcia to the zone? And A-10's, Apaches and F-15E's (of which I'm fairly certain there are some "in theater") weren't enough?
I'm sorry...I still think the B-52 part is B.S., unless they have BUFFs in a "forward area"....hmmm.....
A nighttime assault like this probably went on for hours. But I suspect the Buffs were on station. Given the build up in the area of the Al Qeda forces would have to pull to make the attack our guys probably knew something was up and had them on stand by. Making a truly surprise attack on anything given the massive amount of the intelligence resources available to a modern military is virtually impossible. Look up JStar and see what it can do. Hitting a target where they cannot mask their approach behind normal civilian traffic patterns is virtually impossible for the Terrorists. They simply cannot move fast enough.
FYI, During the initial liberation of Afghanistan they were even flying B-1 and B-2 strikes from Missouri to support the Northern Alliance troops. Using Buffs to support our own troops would be easier then that.