Of course you do! You look at their respective "fruits," or effects, in the real world, and make a comparison; from which one can draw reasonable inferences.
Which results in difference of opinions and beliefs about who does and doesn't suffer from the "observer problem", it seems.
On the sidebar that followed:
Truly, no one is exempt from the "observer problem." And that includes theologians who sometimes wander beyond the revelations of God, fabricating doctrines and traditions of their own imaginings.
Some of them are harmless - like the color of the carpet - or pointless, like ritual washing of dishes. But some of them can be very harmful indeed, especially when they direct hapless followers away from God.
The most common problem vis-à-vis God and the observer problem is the tendency of men to anthropomorphize Him.
For instance, they may insist that God must comply with Aristotlean Laws of Logic. They might say, by reason of the Law of the Excluded Middle, commandments or revelations in Scripture must be either/or and never both.
As another example, they may insist that God must abide by their own sense of an arrow of time and thus cannot judge a person before he comes into existence to say or do anything whereby he would be judged.
By anthropomorphizing God, they deny God who IS and create a smaller "god" of their own imagining, one they can comprehend.