Not really as the changes were deliberate. Given May and Taylor were involved in the story line, it's doubtful anything was an actual mistake.From what Tony says this group failed to do their job
It was done more for supposed dramatic effect. The creation of the Ray Foster character was purely to create drama. To have a "bad guy" from outside the group who didn't believe and who could subsequently be proven wrong. Doesn't get any more Hollywood than that.
The rest of the changes were seemingly to make Live Aid the pivotal point in the band's history. It's pure story telling 101. The almost insurmountable struggle to get there, followed by the all conquering success when they pull it off. If a few pesky facts get in the way of pushing that angle, then just eliminate or change them. Pretty much like every other "based on a true story" movie that's been made.
Why anyone felt the need to tell the story from that angle is anyone's guess. As Tony has said, their story is interesting enough without the factual changes. But at the end of the day it's a movie, not a documentary.