I know it was. There were 5 more successful (and one failed attempt; Apollo 13) landings after it, so unless you claim they were all fake I can't imagine a believable reason why they would fake one and then do a real one (Apollo 12) only four months later.
And if you claim they are all fake I say this.
People make the mistake of comparing a modern laptop costing $1,000 to a million dollar mainframe that had far less computing power and filled a room in 1969 and say that proves technology has advanced enough to make it easier to go to the Moon today. From this they jump to the conclusion that if it still too expensive and difficult today it must have been impossible then.
What they should do is compare a $20,000 car today that gets the same MPG and has the same top speed as a car costing $3,000 in 1969 and then realize that only computers (and all electronics technology) has enjoyed amazing advances while cars (and all transportation technologies including rockets) have not. So it is just as expensive and difficult today as it was in 1969 and still not worth to cost to keep doing it. This is also why so many great robotic missions to planets have flown since then. Because the small, light weight, and highly capable robotic space craft we can build with advanced electronics technology can be easily sent much farther away than the Moon with the same old inefficient and expensive rockets we are still using.
If you compare the appearance of the Moon in the Apollo pictures and videos to what it looks like in the movie "2001, a Space Odyssey", you see they look totally different.