The stars must have been a spectacular sight.

Well, no. True to form Mr. Sibrel doesn't provide any support for this statement; he just drops it as a sort of self-evident fact. But when you look at the numbers, the earth's atmosphere attenuates very little light in the visible spectrum, including light from stars. Objectively, the stars just aren't that much brighter as seen from space compared to seeing them from Earth on a clear night. And to his credit, Mr. Sibrel correctly notes that you can't see or photograph stars simultaneously with sunlit lunar terrain.

Why didn't the astronauts aim their cameras skyward then and photograph the stars with more appropriate settings? For the same reason that doesn't work on earth. Wide-angle lenses on general-purpose cameras are terrible at photographing objects in the night sky. And "the proper settings" in this case still require shutter speeds of 30 seconds or so. The webmaster happened to be in the high desert of California with no clouds on the night Mars was most visible. Fig. 1 is his attempt to photograph the planet using a general purpose camera with a normal lens.

Fig. 1 -The night sky above the high California desert on September 21, 2003. Taken with a sensitive CCD digital camera using its built-in lens and a shutter speed of approximately 4 seconds. Mars -- at its brightest approach on this night -- is the bright spot in the center.

It would have been impossible to get the star field exactly right; even a competent amateur astronomer would have been able to spot mistakes.

This is inherently contradictory; if it's easy to spot mistakes then it's easy to fix them and get it right. The things you get wrong are those things in which errors don't show themselves except under extreme scrutiny. But we can forgive Mr. Sibrel because we know where he's getting the argument. Bill Kaysing, the granddaddy of Apollo hoax authors, said in an interview

"They could not fake the stars and maps because there are too many astronomy buffs, and I've talked to a lot of them. They would have measured the angularity between stars and the position of the stars behind, let's say, the Earth. No way, even with the most advanced computers, could they have created star pictures that would have been, let's say, acceptable to the astronomy buffs."
(www.smaug.org)

The inability to accurately position stars in an artificial display would come as a great surprise to the makers of planetarium instruments.

Fig. 2 -The astronomical Schmidt camera used by Apollo 16 astronauts to photograph the Earth and stars in ultraviolet.

NASA knew they couldn't fake the kind of astronomy that could be done on the moon. That's why they never sent any astronomical cameras to the moon. If they published astronomical photos showing (fake) objects that were discovered not to exist, or failing to show objects that were later found, the hoax would have been revealed.

Fine, except that an astronomical camera was taken to the moon (Fig. 2) and did obtain data that revealed new findings. And those findings are still accepted today, having been verified by other instruments.

Even if we overlook that Sibrel is stupendously ignorant of the facts, the premise is still flawed. If NASA had wanted to publish astronomy pictures taken in space, they could have taken pictures from Earth orbit. The only thing you can't see from Earth orbit, that you can see from the lunar surface, is the Earth itself from a distance. (And Apollo 16 took just those pictures.) Everything else looks the same once you're above the atmosphere.