Not luck at all. First, there are many reasons for eggs to sweat. Your task or learning experience, is to learn which reason.
It appears in your case its a simple case of osmosis. Do you know what osmosis is? In biology there will teach you that osmosis is how plants move water from the ground to the air(out the leaves) Its basically, a fluid moving thru a semi-permeable substance or layer(egg membrane) in this case. From a greater concentration to a lesser concentration.
For you and your eggs its about pressure. Once the amount of water is greater on the outside of an eggs, the water moves inside. When theres to much pressure inside, it moves outside. A delicate balance.
When there is too much water, the eggs absorb to a pressure they expand, then they release pressure slowly, as is their ability. Then they release it quickly, as in your sweating or beading. This is past their design and causes destruction of the outer layers of the egg. Thus killing the egg.
In other words, to much water.
Now consider, eggs do not need to be fat and sassy, They do not need to grow lots. Consider, the more an egg grows, the worse it is, not the better. Of course, some growth is not a problem, in reality, they only need to not dry out.
Snake eggs seem to be very tolerate and succeed in a wide range of moisture. Monitor eggs are not so tolerate, they do not like change. If you attend the monitor forum, you will see(after some time) not many have success in hatching monitor eggs. But hatching monitor eggs is easy.
This leads to a key appliable point and tool. I never measure humidity, or condensation. I never get any condensation. I measure eggs. After all, I am incubating eggs and not water. I simply feel the eggs, if they are soft, they need a little moisture, if they are hard, they contain to much moisture, let them dry out. To feel the eggs, i gently check from the sides of the eggs not the top. The embryo generally is on the top.
In a post above you asked what to do, normally when an egg begins to bead or sweat, all you have to do is place bone dry pearlite on top, to absorb the moisture.
There are other reasons for eggs to sweat, if they are fairly full and die for other reasons, they release water, in this case, they are already dead. In your case, your open egg had red blood vessels, which means its still alive. Of course that could be a product of the camera and not the actual color. Good Luck FR