Did Will Smith get the Nigerian accent well in this movie?

In the upcoming Hollywood 'Concussion ' Debate has begun over the authenticity of Will smith's  accent as some Nigerians on twitter are not convinced he did it well according to online opinion.
'Concussion' is the true story of first discovery CTE (Chronic traumatic encephalopathy)a football related brain trauma which changed the way the USA perceived the safety of it's favourite sport.
Will Smith plays the role of Nigeria-born Dr Omalu.The movie will be in theatres in December.
What do you think?