The annoying thing about a 23:40:26 of Oli's current attitude problems is that they are contradictory and don't make sense.
He has a problem with Elliot because he didn't tell Ollie sooner that Tara was ill. Ollie's reasoning being that he could have got Tara treatment earlier and she might have survived. Except that the only treatment available was surgery so Elliot telling him earlier would just have resluted in her being operated on earlier and as she died on the table, dying earlier. Plus the fact that he did have weeks between Tara telling him and her having the operation when he got nowhere. Fact is, it was Tara's decision and she wasn't going to risk an op until the tumout grew, no matter when Ollie found it.
He has a problem with people being rushed into surgery (presumbably believing that they don't fully understand the dangers) because, we are lead to believe that tara was rushed in and would be alive now if she hadn't been. Except...Tara knew of every potential complication and if anyone was encouraging her to do it, it was Ollie. Her mother had reservatioins. Hell, on the day, jac had reservations because of her raised temperature. Ollie was adamant that it go ahead.
Of course though, Ollie can't accept any blame himself or that ultiamately Tara made her decisions. Much easier to kick out at people like Elliot and Jac - even though it makes no sense whatsoever.
Also, as I've previously said, you always hurt the ones you love, and I suspect that Jac and Elliot are the closest thing to parent (or maybe older sister) that Ollie has. Deep down he knows they will give him leeway - elliot because he is Elliot and great with everyone (except jac) and jac because she and Ollie do have a connection, prodessionally and personally. I doubt that Ric or hansenn would let him get away with it and subconsciously, Ollie knows that.