I am wondering How they know you are using a Direct Ethernet cable and not a wi-fi or cell connection.. (yes it is possible to do it but I wonder)
Is it just that the hardware is provided by work and does not have Wi-Fi. If so man do I have answers (Ubiquity nano station) Some of those are downright impressive.
If they are doing a trace route to see if it's going via a wi-fi router or cell tower... Well Can't help you there.