Also the yellow LAN cable doesn't go into a Mac Air
Aren't both the red and yellow Ethernet LAN cables? Why did he leave 2 of them?
At the very least he should have connected the OR modem to the TT router.
He left without setting modem up!
Do you mean he never even connected OR modem to phone socket? If so, he can't have finished work at cab and it would be pointless joining those cables yet.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC