Margin of error

[cool65]

In the last month, I have had 2 separate infringements for speeding. (the first in 2 years).
Infringement 1 - a 50kph suburban street with stationary car with laser
no traffic in area. Detected 71kph, Alleged 69kph.
Infringement 2 - a 100kph freeway with motorcycle with radar moderate traffic in 3 lanes. Detected 127kph, Alleged 125kph.
I was heading north and there was a 15kph tailwind from ssw.

How can something as accurate as a laser pointed straight ahead, be of the same accuracy as the radar from behind and have the same difference between detected and alleged especially at 50kph higher reading?

Of course the 25kph in Victoria now means a months suspension which I cannot afford as I have bills / family etc.
Really do feel like fronting a magistrate in this case hoping for a 1kph drop so I can keep driving.
Has anyone argued something similar before a magistrate?