(Strip Number 7149, Original Publication Date, 6 January 1985)
Panel 1: We start things off with Lizzie getting a 2 litre carton of milk out of the fridge.
Panel 2: She takes care not to spill any as she pours it into a tumbler.
Panel 3: As Mike and Elly look on in shock, she accidentally knocks the glass over with her elbow and spills it anyway.
Panel 4: Instead of consoling Lizzie or playing the don't-cry-over-spilled-milk card, Elly goes all bitch-faced and complains about the mess she made.
Panel 5: Since Elly doesn't think that Lizzie feels nearly bad enough, she harangues her about being more careful.
Panel 6: She concludes by crying (or, more correctly, bitching) over spilled milk.
Panel 7: As she starts to lecture Lizzie about what to do next time, Elly knocks her coffee cup over as well.
Panel 8: Elly stares at the mess awkwardly for a second.
Panel 9: Awkwardness turns into sheepishness when Mike reassures her that we all make mistakes.
Summary: The big mistake being made here is treating Lizzie like crap on a cracker for something she didn't intend to do. Sadly, it's just another mistake Elly and John keep on making.