If anyone was going to attempt to draw any kind of link up between the injuries and the final league standings then they'd be only considering one aspect amongst many. Owen missed a huge amount of time, but how much actual playing time would he have seen during that time? Conversely Aguero would likely have started all the games he missed. So, although Aguero only missed 14 days on 2 occasions, that equates to probaly 4 or 5 games. It could be argued Owen would need to miss 2 or 3 times the amount of actual days Aguero did to miss the similar amount of actual playing time.
The figures also don't take into account other factors, such as suspensions, International duty or "absences". How much time, in total, did Balotelli and Kompany miss through suspension? Toure through the ACON? Tevez through being a bellend? A great deal indeed, and it could also be well argued that those 4 were all important first team players, players would would start regularly (or always in 2 cases). Cleverley, Anderson and Owen don't really compare.
Personally I don't think the journalist is specifically trying to draw any conclusion from his article, although the subtext is pretty clear. City were stunningly lucky with injuries, United were stunningly unlucky. Combine that with a goal difference title win and many would argue this was the deciding factor in the title race. I don't agree.