Back when I went through my sim partner was an older guy. It was just too fast pace for him and ultimately he couldn't keep up. It also didn't help he barely studied his flows and call outs and otherwise acted too care free about the situation. They worked with him and gave him more time but it was pretty clear he couldn't cut it. I also had a very close friend get through sim only to washout on ioe. They gave him about 100 hours but for whatever reason he couldn't get it. I knew the one lca who was working with him and they all hated having to let him go because he was a likeable guy, but in the end you have to perform and be safe.