Any particle physicist that could answer, what would happen if such a particle would make its way through the atmosphere and hit a person in the head?
It's a bit like how the depth where the energy is deposited of radiotherapy gets deeper with increasing energy. Past a certain energy (hundreds of MeV), most of the energy ends up being delivered somewhere behind you. This particle is hundreds of billions times more energetic than that radiation.
And if it does interact in your head... nothing at all! At such an energy, it is so tiny that at most one electron or one nucleon (i.e. proton or neutron) will get the thrill of its life and find itself leaving precipitously your body in order to smash, a few nanoseconds later, into the planet behind you. You won't notice, and the Earth won't either.
Looks like he survived the incident and even completed his PhD in following years. He did lose hearing on one ear and was partially paralyzed though.
Now the particle mentioned in the article was million time more energetic so...
One extremely-high energy particle is way, way less dangerous than a bunch of billions of less energetic particle... repeated every 25 nanoseconds!
If you don't slow them down, they'll just traverse other uranium nuclei and the reaction will only proceed with its natural speed (half-life of billion of years).
That's why you need a minimum mass of uranium for a nuclear explosion: you need neutrons to traverse a certain thickness of material before it gets slow enough to excite other nuclei