Science makes use of sensory verification when dealing with the details of reality.
When scientists talk of observation, they don't necessarily mean just direct looking, hearing and feeling, wellwisher.
We can use instruments, tools or devices to assist with the observation-part of evidence-gathering.
For instance, whenever we use a telescope, we are not actually observing directly stars, planets, galaxies, etc. For instance, telescope can use different type of lens and mirrors, so what we see are actually refracted and reflected. Direct observation mean naked eye viewing of stars and other objects.
Using telescope isn't direct. And even then these instruments would only view object in the visible light range. There are radio telescopes that allow astronomers light outside the visible spectrum, eg microwave and x-ray capabilities. And if you are using filter, once again, you not really looking anything directly when you have filter on top of the lens and mirrors. And if you want a better view, it sometimes better to use telescope that capable of infrared or near-infrared viewing, give us clearer, cleaner and better resolution than normal optical telescope.
To give you another example, in electrical and electronics, we cannot directly observe the electric current, we cannot measure the ampere, voltage, powers and ohms, with our eyes or ears or nose, and I don't recommend touching any live conductor.
What do we use? We use multi-meters or function generator or oscilloscope, etc.
And when you want to measure the speed of moving objects (eg cars, tennis balls), you would use speed camera or radar speed gun.
Indirect observation is a very important part in science and engineering, and any recording and measurements that these devices, instruments or tools can be used as evidence.
Do you think you can tell someone's DNA just by looking at a person?
Sorry, but you are really being ignorant and narrow-minded, if you think that indirect observation doesn't apply as evidence.