My understanding is that there was supposed to be a delay between the communication from the moon to Earth. Why were the communication instantaneous?
The delay for Earth-Moon communications is about 1.25 second (distance is ~ 380,000 km, the speed of light is ~300,000 km/s). You'd notice this delay only in conversations: every time ground control says something, it takes 2 seconds for the astronauts to respond.
In videos of the live broadcast (search for 'Apollo 11 live ABC') you can hear the delay: ground control says "go for depressurization", then you hear the echo of that coming back from the Moon, and the astronauts' response.
Some modern presentations of the moon landing will edit out the gaps created by the communication delay to make conversation sound more natural, but if you look at the timestamped transcripts, you can verify the 2.5 second round trip delay. Note that the timestamps all refer to the time the Earth-side recording occurred, so the radio delay appears when one of the crew members (CMP, CDR, LMP in the transcript) is responding to the Capcom (CC).