He misremebered the third task as well, since his solution to it, as stated, is wrong. If you aren't given that every card has a number on one side and a color on the other, then you need to check everything which does not satisfy the consequent.
You've still got a problem though, now when you ask the reader to verify the rule, you have to explicitly state that they're not trying to verify the first rule.
Thank you for pointing this out.