Yeah I dont know how Infosys-Fujitsu having a "close partnership" directly implies anything or implicates anyone.

Every big business has dozens if not hundreds of "partnerships".

I dont think someone at Fujitsu managing a big account like the UK post office would go out of their way to screw something up or cover something up because a partner company's co-founder happens to be F-I-L of the UK PM? Like what's the incentive here?