I haven't read Olson's book, and I have no plans to (an Amazon user reviewer wrote "A collection of blog posts wrapped in a self-published vanity piece by a bunch of bat-shit insane conspiracy theorists"), but if his climate denial is anything like his Apollo denial, ignoring it is the kindest treatment you could give it.
The undated article is titled Perplexing Apollo Questions for NASA, and it's a brilliant example of why you should never believe what you read on the Internet. Olson pops up an infographic of the 3-stage Saturn V rocket, and takes us through the fuel loading of each stage and the contribution each stage made to Apollo's journey, ending with "NASA claims that the third stage, called S-IVB, then boosted speed to 24,500 mph and carried the Apollo capsule to the Moon." He then continues with this astounding nonsense:
"Neglecting the necessary first and third stage fuel, we will for layman discussion, assume that the 340,000 gallons of stage twonote 1 are all that was needed to escape Earth’s gravity, therefore 1/6 of that would be necessary to escape the Moons gravity. Given that Apollo must use a similar amount of fuel to slow approach, and use retrorockets to land with another 1/6 to land. Therefore to land and take off, the Lunar Lander would have required at least 1/3 of stage two volume, or 110,000 gallons of fuel.Well, let's see. Stage 2 (S-II) only got Apollo as far as Earth orbit. In "neglecting" the third stage (S-IVB) Olson has neglected exactly what he should be using as the basis for his dodgy calculations. That stage is what enabled Apollo to escape Earth gravity, with 66,000 gallons LH2, 19,000 gallons LOX (85,000 gallons total). And then—astonishing for a man who has some sort of training in engineering—he utterly neglects the comparitive masses of what the S-IVB and the LM descent and ascent engines needed to accelerate.
NASA WHERE IS THE LANDER FUEL STORAGE?"
Acceleration toward the Moon
The mass the S-IVB propelled Moonwards included:
Itself, 123,000 kgnote 2
The Command and Service Modules (CSM) 30,332 kg
The Lunar Module (LM) 16,400 kg
TOTAL 168,732 kg
The thrust of the S-IVB's engines (200 series) was 890,000 newtons
Theoretical acceleration: 5.27 m/sec/sec
Burn time (2nd ignition): 355 sec.
Deceleration on arrival
The CSM/LM stack was initially decelerated by the Service Propulsion System (SPS) engine.
Mass to decelerate: 46,732 kg
Thrust: 91,000 newtons
Theoretical deceleration: 1.95 m/sec/sec
Burn time: 357 sec LOI, 17sec Circ.
The LM descent engine, thrust 45,040 newtons throtlleable, had to decelerate only itself, 16,400 kg. The fuel load was 8,200 kg, approx. 2,000 gallons
Thrust-to-weight in lunar gravity: 1.68
Burn time (Apollo 11): 754 sec.
Acceleration on lunar lift-off
The LM ascent engine, 16,000 newtons, had to accelerate 4,700 kg. The fuel load was 2,353 kg, approx. 540 gallons
Thrust-to-weight in lunar gravity: 2.124
Burn time: 435 sec.
Finally the SPS engine fired again for Trans-Earth Injection. Load 30,332 kg (minus the mass of already-expended fuel), burn time 151 sec.
The SPS engine needed to decelerate 27.7% of the mass the S-IVB had to accelerate, with 10% of the thrust and roughly the same burn time.
The LM descent engine only needed to decelerate 9.7% of the mass the S-IVB had to accelerate, using ~2.3% of the fuel volume (albeit fuel of a completely different kind) and 212% of the burn time.
The LM ascent engine needed to accelerate 2.8% of the mass the S-IVB had to accelerate, using ~0.63% of the fuel volume and 122% of the burn time.
Olson's hand-waving fuel arithmetic is utterly ridiculous.
It gets worse
Olson then shows this drawing, and comes up with this breathtakingly ignorant objection to NASA's description of the mission:
"The claim is that the crew (astroNOTS) boarded the Lander, but there is a rocket engine between these two crafts. ... and it is doubtful that Armstrong and Aldrin ever spacewalked from the Command to the Landing module before and after their “giant leap” ... There is no airlock on the Apollo capsule,note 3 so the cabin pressure would have gone to zero for both exit and entry to the capsule.Of course, the answer is that, once they were on a Moon-bound trajectory and had had the full benefit of the S-IVB's engines, the CSM turned through 180° and docked with the LM, pulling it clear of the S-IVB. I'm pretty sure that many 6th grade schoolkids could tell Olson that, if he asked them.
NASA HOW DID THE ASTRONAUTS GET BETWEEN THE MODULES?"
C2C has seen many ignorant guests in its time, starting with Richard Hoagland, moving on through Mike Bara, Robert Morningstar, Billy Carson, Maurice Cotterell, Clyde Lewis, Bret Sheppard. I think we've found a new paradigm of ignorance.
 The actual figures are 260,000 gallons LH2, 83,000 gallons LOX. Close enough, perhaps.
 Actually somewhat less, since a part of the Upper stage fuel had already been expended in achieving Earth orbit.
 On Coast-to-Coast AM, unbelievably, he actually said "The command module has no docking mechanism".