Golden Delicious are considered to be susceptible to apple scab, fireblight, as well as cedar apple rust, and very susceptible to powdery mildew.
Other than it's ability as an excellent pollinator due to it's long bloom time, it's a poor choice due to it's susceptibility to common apple diseases. It will pollinate most any variety of apple tree.
As far as why that particular tree has not contracted fireblight as of yet while others in the orchard have that are not considered susceptible is unknown.
Is that tree all by itself, segregated from the rest of the orchard?
Once fireblight enters the environment it is very difficult to eradicate. You need to completely remove any trees fully infected and and prune those with beginning sign back at least 18" from the visible sign. In addition, if you let any leaves fall to the ground last fall those will need to be cleaned up as well.
Bottom line, it's easier to fight fireblight before it's an issue than after it is established in the environment.
Here is a pdf that rates various cultivars by susceptibility.
Good luck and remember many common pear cultivars are also very susceptible to fireblight as well so do your homework!