Looking over the list of the New Vegas endings at The Vault wiki, I noticed a couple omissions and a different result.

Chief Hanlon - I confronted him, and decided not to tell anyone about what he did, as long as he joined the Rangers for their stand at the Dam. There was no ending slide.

Crimson Caravans - Got Cass when the Van Graffs wanted her, killed the Van Graffs, turned in evidence to Ranger Jackson. (The quest never recognized the fact I got the Van Graff papers, since I opened the safe first, and the stupid safe doesn't have the papers unless you initiate the quest first. How dumb is that? I did pick up the Van Graff papers afterwards by checking the safe again, but my quest log was not updated) I WAS able to talk to Ranger Jackson about it though and complete the quest. No ending slide.

Fiends - took out three of the fiend leaders, but I did not kill Motor-Runner. Wiki says there's a "weakened Fiends attack NCR, but are repulsed with minimal losses." My ending slide did not mention the Fiends being weakened at all.

I assume this is just another example of a buggy game, but has anyone else had any similar experiences?

You need both sets of papers. One from Crimson also. If you got them both, then yeah; that was buggy. I had Cass all the way til the end and got that one, but did not get anything from having Boone earlier; so maybe you are right. I finished the first go around and anyone I had in my party at one time or another got some kind of slide. The second go thru did not work that way. Wonder if it had something to do with the patch?

Yeah, I got both sets of papers.

Had no slides for Arcade Gannon, even though I met him and asked him to join me (but Boone was in my party.) Had no slides for Veronica - no big surprise, since I never even met her. I did have a slide for Lily, because I found the cure, but I am not sure if I had her in my party. If I ever had her in my party, it was for less than a minute.

Once someone is in your party, they're in your party permanently. You may never use them beyond that first couple of minutes, you may even leave them behind where you found them, but it's enough for an ending slide. If you asked Arcade to join you, he said yes, but didn't because you had Boone and you never went back to pick him up, I think that's enough to keep you from getting a slide.

What if I have a mod that lets me keep multiple companions at once? Does it work too? :unsure2: