Really? No one knows how Willy broke his foot?

[Gretchen]

It seems like at least one person should know

[Kat]

At first I didn't, but now I think it was some mishap with the EBO Time Machine.

Anybody? Anybody?

[MsxBluexSky]

Or perchance the pse stepped on Willy's foot?

[Kat]

Maybe a bunch of Decepticons kidnapped Willy, and John had to pay a ransom of eight bajillion dollars, but Willy escaped out of a nearby window in his captor's abode and fell down a fire escape before John had to pay the price and Willy walked all the way home, being the brave little puppy he is?

Or perhaps that's a bit far-fetched.

[Chip, A Former Ningmaster]

I think it was Part One of Evil Baby Hitler's Evil Eighty-Two Part Plan to take over the world!

[Phineas de Romanus]

*has died from laughing* "part one of Evil Baby Hitlers evil eighty-two part plan to take over the world"

God, that's a mouthful...have you tired saying that outloud, Chip?

[Chip, A Former Ningmaster]

Well, technically speaking, at least two people know. But The Yeti doesn't talk to us and for whatever reason John didn't feel the need/want to tell us.

But Willy's ok now! YAY!

[Debbie (aka Wynflete)]

John did tell us!
A big dog stepped on him at puppy school!

(oh, hang on, ... have I missed the point of the question? If so, then let me rephrase that to say ...
An evil decepticon dog stepped on Willy at puppy school. Could be a story in that! "The adventures of Willy the nerdfighting puppy at Dogwarts the puppy school")

[Phineas de Romanus]

Oh wow, that must have been a big dog!

"The Adventures of Willy the Nerdfighting Puppy at Dogwarts, the Puppy School".........sounds catchy.

[KATY!]

Because Willy is John Wilkes Booth in disguise.

He stole the time machine, went back in time and assassinated Lincoln, broke his foot, and then came back in the time machine.

[Kat]

How'd he break his leg? Did he jump dramatically from the balcony to the stage below?
Willy would do that, the fiend.

[Sasa]

but isn't John Wilkes Booth a decepticon?

[Phineas de Romanus]

Willy must have his naughty (decepticonian) streaks. ;)