Is Akon trying to prove a point ?

Started watching Keri Hilson's new video 'Change Me' and I was thinking hmmm this is a nice track THEN... Akon starting straining out his voice on the bridge - I am baffled? Is he trying to prove how powerful his voice is, because it really aint! Dont get me wrong, Akon is 'OK' but come on mate - this aint working!

Tracks not bad though, check it out: