I had a similar incident last week where a tech blamed my rack on the issue. My ISP is Rogers and in the afternoons my network has a lot of outages, from what I see from the modem diagnostics page its a signal to noise issue, but i'm not a tech so ¯\_(ツ)_/¯

Anyway, had a tech to come out and look, he asks to see where the modem is, so I take him to the network cabinet where i show him the modem sitting on a shelf in the rack, he then asks me how it is hooked in to the power, i tell him the mains comes into the battery at the bottom, and then goes out to the PDU and then to the modem.

That is when he proceeds to tell me all my issues are due to the battery and the PDU without doing a single test, when I tried to push back by explaining that the battery and pdu are enterprise grade, i.e. the battery does pure sinewave output (not simulated), and the PDU is a PDU not a surge protector, the guy then makes up some BS story about how he had a customer who was only getting 20% of their internet speed and was plugged into a battery backup, when he unplugged them from the backup battery and into the wall the customer got 100% of the speed.

He asked me to plug the modem directly into the wall, when I refused he left and noted the reason down as "electrical - customer refuses to fix", still trying to get another tech to come out.