According to Max's own comments after his SLC skates, at least two issues were involved in his mistakes:
Although he referred to the "mental game" as one of them, another factor was his focus on making his movements big, which has the risk of getting him off balance.
I would add that based on what other skaters (and perhaps Max) have said at other times, it is possible that excesssive concentration on the task at hand does not help -- and in fact could hurt, leading to mistakes that a skater never makes when training at home. I've read/heard many skaters talk about the importance of trusting their training when competing and letting muscle memory take over.