Your summary seems pretty accurate. I don't think there were many programming errors outside of P's meltdown, though. Also, as has been touched upon elsewhere in these comments, some of the failures to maximally exploit simple bots were necessary side effects of the attempts to trick complex bots, not just failures to anticipate there being a significant number of simple bots at all. (Sort of a quantitative instead of qualitative prediction mistake--we just thought there'd be more complex bots than simple bots).

One clue towards the general simplicity of the field is the generally atrocious formatting (e.g. close-parens on their own lines)--not many people seem to have had too much experience with Lisp, let alone Lisp projects as complex as this game can get. That's a shame, but it's not like any non-Lisp languages are remotely suitable for the kind of source analysis we all wanted to see in this game.