Idiom: 'the balls on this one'?

[Torsten]

Hi, I have a rough idea but maybe you can explain the meaning of this phrase: 'the balls on this one'.

Here is the context I've come across it. The commander of the Swiss Guards is very angry at a female scientist:

"....Che coglioni che ha questa! he thought. The balls on this one!"

Thanks in advance,
Torsten

TOEIC short conversations: An employee asks his co-worker for small change

[Conchita]

[Jamie (K)]

Balls here means testicles, and therefore masculine-style courage or assertiveness. It can be very insulting when used in regard to a woman, but not always. We say balls where other languages say "eggs".