High-quality conductors can improve performance, but only a bit, in this case; when it comes to length the problem isn't resistance, it's the capacitance of the wire (which is a function purely of length). The longer the run length the higher the current needs to be to achieve the same voltage. Ethernet's run length limits are based on calculations to determine the point at which the signal in dB is too low to be reliably received. The latency he experienced probably wasn't to do with the length itself, but with the fact the packets had to be retransmitted multiple times before they were successfully received.