There was just the one security camera.
All the shots from other angles and close-ups, all that was “flashback” footage by the Russos for storytelling purposes. The characters watching the in-Universe footage knew what they were watching but, if that one camera angle with no change in framing was all that had been presented to the movie audience, the internet would be lighting up with people saying it was ambiguous and we don’t know what really happened and secrets will be revealed in future movies and if you pause it and zoom in at the exact right second and squint you can kinda see a shadow that looks like it could be Black Cat.
The flashback footage intercut with the in-Universe security camera footage is a storytelling device to make sure the audience gets exactly the information that the filmmakers want to convey with no ambiguity. It’s presented in a stylized grainy way so that it doesn’t jump out when cut to from the security camera footage, but that’s just stylized for effect. It’s flashback. The only actual footage came from one security camera.
Winter Soldier’s instructions were to acquire the blue raspberry Powerade from the trunk of Stark’s car and to leave no witnesses. No witnesses means that the Starks had to die and Winter Soldier, being a good Employee of the Month kind of a Winter Soldier, would also notice the presence of a security camera and incorporate his “No Witnesses” instructions to include smashing the camera and retrieving the videotape.
I really liked getting a Spider-man who looks so young. Sure we were meant to believe that Tobey Maguire was in high school in the early scenes of his first Spider-man movie, but he really didn’t look it. Ditto Andrew Garfield.
The 2008 The Incredible Hulk is officially part of the MCU even though they recast Banner from Norton to Ruffalo. The Abomination survives at the end of the movie (and is referenced in the first season of Agents of S.H.I.E.L.D., Coulson tells Ward “I’ll have you stationed in Alaska guarding Blonsky’s cell”), and he’s also referenced in the Marvel One-Shot short film The Consultant as the World Security Council question whether Blonsky could be rehabilitated and brought into the Avengers initiative.
The 2008 Hulk movie shows the origin of The Leader, who also survives. Apparently, his whereabouts are addressed in a MCU tie-in comic book.
It may almost seem like the MCU has disavowed the 2008 movie but then again they’ve just brought back William Hurt as General (now Secretary of State) Ross. So, I say that The Abomination and The Leader still exist in the MCU (though I doubt we’ll ever see them again).
Justin Hammer* is still alive but he’s not quite a supervillain.
Red Skull was sucked away into another… dimension? Galaxy?
I think his fate was intentionally left ambiguous in case they ever want to bring him back.
The real Mandarin has been established. In the Marvel One-Shot short film All Hail the King we find out that the real actual Mandarin does exist and he’s none too happy with Trevor Slattery’s performance as an imposter- it’s implied that Slattery mave have been killed as punishment but at the same time it’s established that the real Mandarin does exist in the MCU.
Batroc the Leaper* survives The Winter Soldier, not quite a supervillain I suppose.
And who knows if computer-Zola is still on a hard drive somewhere.
Ulysses Klaw* survives Age of Ultron, with his arm not insignificantly torn off. Could possibly rise to supervillain status once outfitted with his prosthesis if he ever returns.
Mitchell Carson* survives from Ant-Man, though probably not a supervillain.
And, of course, Thanos is still out there- but that’s as planned.
*Actually, upon preview, I see you’re counting Zemo as a supervillain. If Zemo counts as a supervillain (questionable), then Hammer, Batroc, Klaw, and Carson should count as well.
ETA: Oh, and Nebula survives from Guardians of the Galaxy