It says conscious can't be divided, but that's not true as far as I know.
https://en.wikipedia.org/wiki/Split-brain
"In a more serious effect, the patient may have two different consciousnesses, one on each side of the brain."
https://en.wikipedia.org/wiki/Split-brain
"In a more serious effect, the patient may have two different consciousnesses, one on each side of the brain."
To respond to your comment, it seems that brain damage, psychoactive drugs, and transcranial magnetic stimulation are all evidence that, even if a "consciousness" can't be split in two (contradicted by your reference), parts of it can be removed or altered by altering matter, so it's still most likely a simple physical process.
In other words, one of the properties of the subjective experience of consciousness is that of a unified whole.
In the experiments you link, the two consciousnesses are not aware of each other, and presumably(?) don't experience the other, thus they are two separate, individual consciousnesses, each experiencing themselves as an indivisible whole.
In other words, these brains host two separate consciousnesses, just like our two skulls host two separate consciousnesses (in two brains). Whatever wiring links up aspects of the brain that gives the perception of unified conscious has been sundered.