Since we're into repeating ourselves when OP's repeat themselves:
(1) You have no direct knowledge of what was said, you weren't there.
(2) It would be a massive violation for the clinicians or anyone else at the hospital to talk to you about anything. If it was the police, it would be unlikely for them to have a casual conversation with a third party about the specifics of any case.
(3) If your friend was initially placed on a 3 day hold and that was extended, through a court order, to a 25 day hold then something else was communicated to the doctors that seriously raised the level of concern.
(3) The RA had to call the police. There was no real option given what was reported by you.
(4) It's possible that your friend gave you an explanation that had a few rainbows and unicorns it, gamboling on a lovely green meadow.
(5) Not all suicides are people that broadcast obvious signs. It's like serial killers, "they were so nice and quiet. They would watch my kids for me when I went to the store.". You just don't know what's happening below the surface.
Certainty is young persons burden. Most of us, here, have been relieved of carrying that load and feel comfortable saying that we don't know everything. I feel comfortable saying that people are truly difficult to know. People have many faces. One that they show to the world, at large, one that they show to friends, one that they show to loved ones and the last is the one that is hidden. There are many shades and more faces, the ones I list would be the most common. Honestly ask yourself which face you're seeing. It's not an insult that you don't see that hidden one and some bury that last deeper than other but we all have it. Even those who claim to be an open book.