Visible crew/equipment: A reflector screen is visible on Hawkeye's sunglasses at the very end when Thor and a restrained Loki are returning, presumably, to Asgard. (02:06:10)
Visible crew/equipment: In the extra footage after the credits, the reflection of the crew is visible in the picture frames around the apartment.
Visible crew/equipment: After Doctor Strange experiments with the magical doorway in the Sanctum Sanctorum, he leaves it on a desert view and we cut to a shot panning across all the artifacts. At the very start of the shot on the right hand side of the screen is a crewmember standing in the shadows looking bored. Really blatant if you turn up the brightness, but easy enough to spot if you know what you're looking at. (00:56:00)
Visible crew/equipment: When Natalie and Pepper arrive at the Expo and open the car's door a huge lighting screen gets reflected on the door. (01:32:30)
Visible crew/equipment: When Nick lights his lighter to burn all of his stuff, two white screens are visible in his glasses. (01:59:00)
Visible crew/equipment: When the team are discussing the time heist following Barton's time travel test, the Steadicam operator can be seen walking to the right in the reflection in the glass behind Tony Stark. (01:02:23)
Visible crew/equipment: When Peter approaches Happy in the beginning, you can see the camera reflected in his glasses. (00:06:26)
Visible crew/equipment: When the President boards Air Force One with the Iron Patriot you can see the reflection of the camera boom and crew in the two black cars in front of the plane moving to the left.
Visible crew/equipment: At the end of the movie, when Captain America and Black Widow are walking towards the camera to train the new Avengers, the reflection of the cameraman's feet are seen on the glass railings in the back as they walk backwards shooting the actors.