@JoshHack I'm speaking to what I've witnessed since the eggs started hatching raid bosses again. I know all the spoofers in my area, they haven't been spoofing like they used to but now they are showing up in gyms again. When a level 5 egg appears atop of a gym that is controlled by say team Instinct are you still able to battle it if you are on an opposing team? I'm asking because I haven't been able to play as much as I like and confirm this personally but I assume that it is possible because thats how the old egg system worked. With that being said, if you are able to battle an enemy gym while there is an egg atop a gym and claim it for your team then you will be awarded with a gym ball bonus after beating the raid boss that hatched from the egg that your team has control of.
What I'm getting at is: I've witnessed an increase of spoofers in gyms most recently. I believe it is because once they know of a level 5 egg they want to claim that gym for their team in order to get a ball bonus and increase their odds at catching a legendary dog. So my question is, can you battle a gym that has an egg on top of it?