What's wrong with this picture?

Local IP: 192.168.107.78 Netmask : 255.255.255.0 Gateway IP: 192.168.10.1

Exactly what is wrong with this picture?

It was the network setup of a client of mine. And if any of you can understand how a network works, you will see that this configuration will not work. And this is quite true. BUT IT DOES WORK!!! Windows seems to take no notice at all of this strange thing called "standards" and connects to the gateway using the local ip completely ignoring the subnet mask.

Linux on the other hand, threw a hissy fit and refused to have anything to do with it. And I really don't blame it. Those standards are there for a reason and the reason is security. So there I was, faced with a problem. If I tried to fix this screwed up system I would have to go through a massive process of convincing people that their system was wrong and that they should start using one subnet. This would be great if it were something that could realistically happen. So I took the path of least resistance, changed the netmask to 255.255.0.0 and took the cash and walked out the door

What would YOU have done?