Other mistake: During one of the recording studio scenes, there's a short segment that shows a bunch of VU (audio level) meters close up. The very first meter in that sequence is not a VU meter. Its from of an old HF (High Frequency) Amateur Radio transceiver; The scale is marked for RF, SWR, and ALC. I'm suspecting that someone involved with the post production editing is a Ham.
Other mistake: When Elton visits his father late in the film, his half brothers mention that there is a Rolls Royce outside. However, Elton enters a yellow cab when he is leaving the property, and then is shown in the Rolls Royce further down the road.
Other mistake: After Elton get a off the phone with his mother in the phone booth, he gets into an argument with John Reid who hits him in the face on the left. In the next scene when Elton is putting on makeup before a show he is covering up the bruise on the right side of his face.