Moss

if you watch iron lung with an ava-centric perspective (which involves heavily blacking out during most scenes where the radio isn't on, only do this if you have a really good grasp of the film) you start to notice how extremely weary and sad she is. like, the entire time. from the beginning. she's harsh, but she is not cruel to simon. she's angry with him, but its mostly because, from her view, he's backing out of the deal they made because he, what, got scared? she doesnt have time for dealing with outbursts and overreactions, so she yells over him because that makes him listen, and then she keeps yelling because he keeps listening to that. she tempers his expectations from the beginning - he starts talking about going free as soon as he collects a little bit of data, when she believes that the deal was to finish a full dive and gather as much information, samples, photos as possible. she tells him again and again that his job is not done yet, and he chooses to believe that means he's going free as soon as he finishes her next step. she has a crew to look after. she has a responsibility to integrate him into COI society and she cannot do that until she knows he's going to be okay with the way the collective works - orders and missions, duty rosters and strict scheduling. at every point she is as honest as she can be - as @itsgotgills pointed out, the only time she really intentionally lies to him is when she's telling him that he is the first down, he's the test driver - and it's probably because her last convict killed himself at the bottom of the ocean, wasting time and resources and neglecting to gather any data. she can't risk another failure like that - they are literally running out of food, water and air. if you listen - "all we have are surface scans, that's why you're there." sounds rehearsed, almost bored. (and it's not bad acting. we know how good caroline kaplan is.) her immediate follow-up, though- "well. one of the reasons." sounds genuinely angry. THAT is ava. that's her, sick of the consolidation's script, sick of eden's destructive bullshit, taking it out on the one person she has to hand, reminding simon of his position - lucky enough to have survived the filament station tragedy, lucky to have survived the consolidation, now lucky to be allowed to finish his realisation and rejoin society. (is this a correct worldview? definitely not. but it is ava's). she is still working under someone else's orders. her choices are shaped heavily by the consolidation and she mostly believes in them, but sometimes - and increasingly often towards the end of the film - she doesnt. her response to simon's "i would really, really like to not be down here anymore." - "yeah, i know. i don't think that's possible." she holds off letting him know that she's been ordered to leave him down there, and she sounds so very tired. as soon as she realises there might be something worth diving for, she becomes genuinely enthused, completely determined despite the consolidation's direct orders - she starts to act for herself, in the interest of her personal goal (saving humanity, survival. altruism queen). she's genuinely, truly at the end of her tether. there is nothing she will not do for a little bit of hope - sacrifice the health and safety of her own crew (jack), directly contradict COI orders (sm-14 dive), risk her own life (piloting the 14 alone), even dying to ensure the black box gets to the surface. every line of dialogue, every action she takes, every order and decision is all in the name of survival - she has no interest in hurting or killing convicts, because she needs them. she's been doing this for twenty one years and she is so deeply tired and she is doing the only thing she can to try to provide a future for whoever comes after her.