What are the parameters for 'stealing' resources? (Minors issue)

Early on in Alpha there was talk about control of resources and what happens if you have two constructors plopped down on the same resource. Who controls it?

At first the rule was whoever gets it first. 

However, I have had several resources 'stolen' AFTER I had an established mining base on them. Is this possible or is this a bug? I tried to put more modules such as mining or whatever to steal it back but could not. 

Ultimately I DoWd the Minor and destroyed said offender. I would like to know if this is working as intended or if it needs some tweaking or its a bug.