What's happened is CONTROL and TELMU have blended together onto CONTROL's loop, and unfortunately there's about a 1-second delay between both transmissions so that's why it sounds like there is an echo. The TELMU channel on the website is nonfunctional at least during this phase on the mission. I think later on, they begin to separate out.
I thought Glynn was just about ready to lose it when INCO said there would be a 2-minute data loss for some reconfiguration and it took 20 minutes or more. INCO even on the FLIGHT loop just after the accident is interesting to listen to, as the controller is incredibly laconic and calm but one can tell a lot is going on behind the scenes.
There was indeed a lot of off-radio chatter that you didn't hear on the tapes.
Lunney has TELMU (Merlin Merritt) in his ear both on and off the loops begging him to get the power load reduced, and the flight dynamics people are champing at the bit to get the spacecraft on free return, so Lunney is impatient to get good comm established with the crew. It's very clear on even the FLIGHT loop that he has a difficult time hiding his anger over the comm being lost for a long period of time. Throughout the INCO loop during that incident, you can hear Ed Fendell make remarks like "I have to fight the flight director off -- here he comes" and "I've got a monkey on my back now" and "you guys have really done me in", which would seem to indicate he got chewed out off the loops.
A similar incident happens toward the end of the mission when the CM (now separated from the service module) is performing its final alignment prior to LM sep and re-entry. INCO (Tom Hanchett) struggles to establish comm and data with Odyssey during a phase of the mission when GUIDO (Ken Russell) and YAW (Bill Pressley) are in a hurry to uplink commands, losing data four or five times in the process. Gene Kranz, as steely as they come, has a better time concealing his anger than Glynn Lunney, but even he lets out an audible sigh of irritation over the loops after they break lock for the third time. "INCO, what's your problem?" When they have an opportunity to go back on high bitrate after downgrading to low to lock on solid, Kranz refuses INCO's request to do so, having lost faith in the stability of the comm.
It's important to note that Fendell and Hanchett are very competent men, having been involved in the space program for years even through the Mercury and Gemini days. The procedures, however, are only as good as the training that they receive. So when the flight controllers write up the mission operations report at the end of Apollo 13, both INCO and PROCEDURES will openly slam the poor quality of the sims as far as communication failures are concerned:
A number of attempted communications failures have been incorrectly simulated such as an attempt to fail the entire USB downlink but failing to inhibit the crews downlink voice. These mistakes provide INCO negative training in resolving communications anomalies as well as causing the Flight Director to lose some confidence in INCO."
As far as the spliced INCO/PROCEDURES loop -- I'll upload them on Google Drive and share a link at the next most opportune time!