Here is a Youtube video with the ground communications only, and a fixed view video camera at Mission Control, with many SpaceX employees in the background (other side of a glass wall). Go to just before 29 minutes in the video. You’ll see some reactions by people, particularly the SpaceX president and Chief Operations Officer (COO) near the center of the front row.
https://youtu.be/-B_tWbjFIGI?t=1720
[video=youtube;-B_tWbjFIGI]https://www.youtube.com/watch?v=-B_tWbjFIGI[/video]
And BTW, for those who do not know, the SpaceX president is Gwynne Shotwell. And the COO is Gwynne Shotwell. Credit for SpaceX’s success goes more to her than to Elon Musk, I think. So it is neat to see her responses to the launch, and to her employees at some key moments.
Final count for launch beings at about 29:40.
Side boosters start to throttle down and prepare for separation at about 32:20
Core shutdown for staging at about 33:00
Faring separation at about 33:42. They see the real-time internal view of the Tesla, with the fairing separating, that wasn’t originally shown in the webcast.
Side boosters entry burn at about 36:30, center core entry burn shortly after.
Side boosters subsonic at about 37:30, shortly after their landing burns begin, center core a bit after that.
Side boosters land at about 38:00. Crowd goes nuts.
Center core begins landing burn at 38:18, igniting center engine. Very soon after, two more engines were supposed to ignite very shortly after but did not (ran out of TEA/TEB).
At about 38:28 they react to the center core crashing, as “we lost the center core” is said over the communications. I do not know what arrangement they have for real time displays, but I would figure they have many VERY large monitors, so very likely they had one showing the onboard (Cineroc-ish) video (which had seemed a bit blurry after the re-entry burn), and the video from the ASDS. If they had any decent view from the onboard camera, then they would have likely seen that it was going to miss the ASDS and the ocean surface coming up way faster than it should have then loss of signal from the core. So, while they often lose signal briefly on the ASDS due to exhaust acoustics affecting the communications antenna dish, they probably saw the crash from the camera on the center core. Also, moments later from the ASDS camera, the mist from the splash-crash was moving, so that wasn’t a freeze frame or smoke from landing. Most likely on the webcast we saw, the director knew it crashed and quickly changed the video feed before it became obvious that there was live video from onboard the ASDS that would have been showing no Falcon sitting there as the spray/mist subsided.
So, this shows why the crowd got so silent so quickly. They probably all saw the crash. On the webcast we saw, presenters sure seemed like they were about to say it had crashed, but it seemed someone told them in their earpieces NOT to say so. So they began their routine of dancing around the subject (acting like they did not know the outcome - they need to take acting classes if forced to do that kind of thing again).
Anyway, a really interesting perspective on how the people in the room reacted to the launch. Also, while its “Mission Control”, during the pre-flight pose its Launch Control in charge, though the last few minutes it’s the Falcon onboard computer in charge but Launch Control can override to do a hold/abort until the last 10 seconds IIRC. Once it’s launched, NOBODY has any control over the launch vehicle, it’s 100% automated (even the self-destruct is automated now). So, back to Mission Control, they are in a real sense spectators for the launches. Monitoring what is going on, real-time data on performance values, flight path, and so forth, seeing if it’s “nominal”, or if there’s a problem occurring (that they can’t do anything about during launch).
Update - I looked around and found some images of SpaceX's Mission Control. They use one huge projection screen (seems like a projection screen). So, like a computer monitor with a lot of windows open on it, showing the various views of whatever things are most important to show "on the big screen" at the time. In this case, a CRS resupply mission with a Dragon at ISS.
BTW - the page I found the image below on has a lot of interesting photos on it, about SpaceX and others. Worth going to it and scrolling thru all of it.
https://factualfiction.com/marsartists/category/sets/page/3/