The Calculus Affair: Part 2 - S1-E13
Character mistake: After reaching the border, Snowy finds an umbrella and Tintin states that it is Calculus's umbrella. It isn't Calculus's umbrella - Calculus's umbrella has a brown handle, and this one has a grey handle. (00:42:25)
Character mistake: When King Koopa runs away from Kooky's machine, he says for it to let him go before he is grabbed. (00:08:13)