It isn't as simple as merely blaming the G4S management (for not knowing what was going on).
This contract has been set up with performance deductions, such that the monthly contractual sum can have payments taken away from G4S if certain targets are not met.
One of the targets is no instances of fighting between 'customers', or 'customers' attacking the custody officers.
That's a completely ridiculous target to set any contractor in these circumstances, in particular because the contractor has limited ability to control it, and the customers are inherently troublesome little chaps who undoubtedly know that G4S has this penalty regime running on them.
Already, so the idea behind it is that the contractor establishes a working regime that encourages cooperation of the troublesome little chaps, but that's easier said than done.
Easy therefore to see how the easy way out of the operations people is to instil fear to quash potential trouble.
You can probably blame consultants for thinking those performance penalty parameters - far too clever to think the Youth Justice Board derived them.
Not the whole problem, but G4S were stupid to accept the performance regime terms.