Default Risk for Government Bonds default, recovery, around, price

ikoreaii

Schweser says: "Government bonds are default risk free but are subject to price risk."

IMHO, thats bullsh*t. It would be ok if we still lived in 2007.

Shouldn't we consider a default probability for any bond?

And why is there a formula to calculate the implicit probability of default (given the CDS) - even for US, German or UK-government bonds or any other AAA bond - if there is no default risk at all?

P.S. Assuming a recovery rate of 50%, the default risk for a 10y US-Gov-Note is around 10% (I know that CDS overestimate the probability of default, but still - I won't say there is no probability or "virtually" no probability of default.)