Though source is Wikipedia, only a small section is about the Mutiny (Macedonian Conquest). References of the original sources are below (as all 'wiki docs are). Wikipedia, though generally disapproved of by teachers, can be reliable and in this case, I do not believe the reliability is as significantly important because the source only gives a brief overview of the event.
On Apr 22, 2010 Joseph Roisman published: Why Did Alexander's Army Mutiny in Opis? Author's opinion backed up with evidence from variety of primary sources (Arrian included) ((Is only an excerpt from the entire document; have to pay for the full 'doc)). As mentioned, the source is backed up with primary evidence (and secondary) and so as far as the evidence of the author's claims are, the information is reliable. However the actual author's presentation of the event could be indirectly bias (within the avoidance of sources that would show a different opinion). I do not think this is the case as the author presents more than one suggestion for the cause of the mutiny and the actions taken after.