When Krell first addresses Rex by his designation number, Krell's goatee is missing.
When the gunships are descending, there are 6 gunships. One gunship gets shot down, making there be only 5 gunships. However, when the gunships land, there are 6 again.
General Krell refers to Captain Rex as "CT-7567," even though Rex's original number was CC-7567.
When the gunships are delivering AT-RTs, it shows that a gunship can only carry one AT-RT. Later it shows about 10 AT-RTs charging into battle, proving more gunships were deployed than were actually seen.