To tip a cow over on someone

[Chicken Sandwich]

I was just watching The Big Bang Theory and this line came up:

I bet Leonard never tipped a cow over on himself.

What does this mean? I couldn't find this saying.

Thanks in advance

 

[emsr2d2]

I was just watching The Big Bang Theory and this line came up:



What does this mean? I couldn't find this saying.

Thanks in advance

I don't understand the line itself (some more context might have helped, I'm not sure) but here's what cow tipping is.

 

[Chicken Sandwich]

Penny: I kinda told my father we got back together again.
Leonard Hofstadter: What? Why?
Penny: Well, you're the first guy he's ever really approved of, you know, you're a scientist who went to college, and you don't have a neck tattoo or outstanding warrants or - or a baby.
Leonard Hofstadter: What kind of guys did you used to go out with?
Penny: Just guys. Anyway, when I told him we split up, he was heart-broken, and he kept bugging me: "How's Leonard?", "Why can't you get back together with Leonard?", "I bet Leonard never tipped a cow over on himself."

 

[Barb_D]

Her father had just used that as an example of how stupid or inept Penny's prior boyfriends were. They were so dumb that even the simple (mythical) act of cow tipping could not be done competently.