A direct corollary of this is the confusion of young people who think and act as though online interaction with someone whom they have never met in person or spent face-to-face time with, is a relationship.
Confused, sad, pitiful.
They are confusing the dry, definitional meaning of relationship with the real-world, practical definition whose implications are the real and full content of the human experience.
All cherubim are seraphim but not all seraphim are cherubim.
Relationships are multi-dimensional ... and not the narrow reality of a merely abstract pen-pal-like interaction. The narrow content of electronic interaction is just one aspect of the whole of our reality ... but just one part ... and by comparison to the multi-dimensional, synergistic, profound nature of our real-world existences ... just one anemic, watery, narrow part.
Humans have hundreds of thousands of years of evolution, both physical and societal, which has been formed by the full reality of our physical, mental and emotional experiences, and all of the interrelated effects that each of those spheres has on the whole.
Since the scourge of commercially propagated gaming addiction and online and electronic communication; peoples increasing unwillingness to distinguish between the full spectrum of reality and the insular, narrow scope of artificial reality has spread rapidly like crack addiction ... and uses some of the same electric circuits in our heads.
It is both faddish infatuation with this new electronic whiz-bangery, and also the succumbing of our humanity (what makes us human - particularly in society) to artificial stimulus .
A type of stimulus-addiction that is analogous to someone being so addicted to masturbation that the rest of their lives suffer ... suffer both from the time it takes from their limited allotment of time that fate will give them (to be what by anthropologic standards, is "human"), and also the *health* that actually dealing with reality, provides.
Now ... with regard to your specific question ...
I am not surprised that the attackers did not, or would not, distinguish between reality (the tragedy of losing someone in the physical world) and the game they were playing.
Btw: It is completely notwithstanding that her interaction with everyone involved was through electronic gaming ... every single person knew that she existed as a real human being with the same needs and wants and loves ... and divinity ... that we all have.
If they reacted that way because they are jerky human arseholes ... then fine ... humans have acted abominably to each other since the dawn of civilization.
If they acted that way because their minds have been warped (a really good term for this) by their unnatural insular interaction with electronica, then that is the manifestation of an unfortunate pathology that we are likely to see more and more of as people struggle to remain human in the face of interacting electronically while as a consequence their personal character slowly dissolves ... as it does in substance abuse.