Several segments of the "armor" attached to the cars appear to be sheet metal, which would not offer protection from bullets.
As the lookout falls the platform, he stops in mid air (for a spit second) just before he hits the ground. This reveals that it was a completed stunt fall, that then had additional CGI to complete the supposed height of the on-screen fall.
After the Saviors' convoy is hit with a roadside bomb, part of a roll-cage can be seen through the driver's window of one of their overturned cars, indicating it has been reinforced structurally for stunt purposes.
In one scene, one of the armor plates on the Hilltop's cars can be seen flapping in the wind, indicating that it's a prop.
When Rick is giving the opening speech, there is a plane/contrail in one shot.
The first time Tara checks the time on her watch she says the time 10:28 out loud then later she checks the time again a second time in which she repeats the time 10:28 again.
An airplane leaving a long trail behind can be seen above Rick's head in the opening scene, when Rick is giving his motivating speech.
Ricks strategy is to try and kill Negan and get the other Saviors to surrender. However, despite Negan standing a short distance away from him, Rick declines to shoot him.
In seasons 4-7, the walkers were so attracted to fire that they would walk into it (contradicting earlier seasons). Here, they are just walking past each fire toward the next. At the same time, they are suddenly more interested in one of these farther away fires than in Daryl's loud motorcycle - Again contradicting past scenes.