Deliberate mistake: Zhang crushed and smeared several long red-hot peppers (cayenne?) in his hands to use as a makeshift weapon against thugs when rescuing Mei Mei. After Zhang smeared and pushed peppers into one thug's eyes, it is unlikely he would have been able to retain as much of the crushed peppers in his palms as he did. Also, holding the peppers in one or both of his palms would have interfered with grasping the second thug and redirecting his gun (without sliding off). (00:08:00 - 00:08:50)
Revealing mistake: As impressive as the CGI lions were, there are almost always giveaways. For example, when Fareeda calls Charlie over and goes to hug him, her left hand and forearm quickly disappear into his mane and go too far in to be realistic. There is also a small but noticeable gap when Charlie's right paw is curled over Fareeda's left shoulder. (00:18:45)