Mick McGuane has had a year at the club helping with scouting and coaching (apparently unpaid).
He has a pretty impressive coaching record, having coached Burnie to a premiership 5 years ago and then transforming Gisborne from a team of easy beats into an almost unbeatable force. This is surely more relevant to whether he should get the Coburg job than mud-slinging about his personal life.
Coaching his nephew could possibly present him with some dilemmas but may also cause none. I'd be very surprised if it was a consideration in judging his suitability for the job.