I'm starting to wonder if people will blame Mercedes after all she did say she was going to get her 'Sweet Revenge' before she changed her mind and accepted

As much as I dislike Joanne and would love to blame her it has to be Cameron's fault really.

Joanne is a bunny boiling stirrer and trouble causer, she plays mind games, but she isn't a physical harmer or killer. Cameron, unlike most killers on HO, doesn't care about collateral damage or who else is harmed or killed when he gets a red mist about his intended target. Sure Nico was his one intended target but at the time he didn't give a rats about who else it would put in danger. Similarly when he caused the explosion at the house the safety of innocent strangers on the street or in adjoining houses didn't matter.

Cameron.
Regardless of what Joanne did, the cherry picker was there rescuing Mercy and Joe so the fact the big wheel was halted did not result in his death. Cameron started the fire.

BUT why didn't the fireman who was in the cherry picker with Mercy help? Joe jumped and was hanging on, and the fireman just sat there while Mercy was trying to pull him up by herself. With the help of the fireman they'd have easily pulled him up!
Also why was the cherry picker suddenly further away? mercy climbed over easily enough and in the next shot Joe had to make a running jump!

Exactly this. It is bad enough that he is willing to kill anybody he deems a threat to his relationships with Peri, he is completely uncaring as to what 'innocents' could be hurt or killed in.the process. We saw this in his reaction to Ziggy
S death (which he joked about to Lachlan) and Joe's where he juat looked like he was mentally shrugging his shoulders and forgetting about it.

Anybody could have been in that maze, he didn't care. Residents of houses ir flats next to or above Leelas as mentioned. Even the Lomaxs, somebody could have crashed into them after they'd crashed, it could have become a multi pile up.

But he doesn't care about that.

I love how when Joe was hanging off the cherry picker, the fireman who cowering in the corner and not helping *smh* poor Joe, I had grown to like him even though he could be frustrating at times. I liked his relationship with Mercy but it was kind of ruined with the Joanne thing.
Cameron, Joanne and HO crappy emergency services all have fault imo.

Was it actually a fireman un the cherry picker? I didn't notice a uniform and wouldn't they have used the fire engine ladders and probably safety ropes or a fireman lift?

I'd say it was a member of the Fair Organisers maintenance crew so maybe he hadn't been trained so didn't know what to do or just froze? Or even as something as daft as not being insured for rescue work and nit wanting to be sued if heceas the pne yo lose his grip on Joe?

All pretty crap reasons but possible.

I assumed the fireman was knocked out. As to who is to blame, both Joanne and Cameron are equally to blame.

Cameron is to blame, his actions led to the Ferris wheel ending up how it did, Joanne was an accomplice.

Joe would never have died had she not tampered with the Ferris wheel. Although I guess you could argue that Joanne was fully responsible.