Not a legal expert by any means but have unfortunately met a few coroners. I think the coroner can make recommendations but these are not legally binding. It seems he can pretty much say what he likes? As an example, say a person died in hospital as a result of medical negligance, this may become apparent during the inquest but the coroner would not be in a position to take action against anyone involved, that would be for other courts. He does apparently say at one point about having no powers to ban race officials etc. Any "blame" he has made is perhaps not the same as "blame" in other court proceedings which would be a whole different ball game.
Not being from the IOM I don't know of this guy but it's clear he is well liked and I'm certainly not trying to defend him!
Also, I don't think any official reports are released of inquests in IOM so we just have news reports to go on.