Yeah Stauffer reported multiple times that Chiarelli famously made all the decisions himself without any sort of committee or other voices in the room. He was hyper independent and the rest of the front office was out of the loop with his transactions.
Chiarelli dealt with Neely's backseat driving and meddling in Boston, getting pushed around a lot by the looks of it. Eventually he got fired.
In Edmonton, the Oilers just won the McLottery and were starving for a GM with any sort of credentials and gave him free reins.
Chiarelli strikes me as conflict averse and a poor negotiator, so it's like he was trying to prove he wasn't afraid to do stuff that might be controversial. Signing Kassian (which did work out well, granted) or that completely inane Manning trade (not just because of the history with McDavid, but just him being a #7 D at like 2.5M, ouch).
Towards the end of his tenure Chiarelli had completely lost the plot. The Eberle for Strome for Spooner fiasco, the aforementioned Manning trade, the Alex Petrovic trade, the Koskinen signing etc.