The suited guy in the video is an employee from the office of materials that goes into the wilderness to test if it would have been possible to create a fully functioning telegraph with stone-age tools.
Guess what? Using no modern tools or materials and relying entirely on material found on the ground in the wilderness, a telegraph switch producing .7 volts of electricity was completed. This shows that – if only one had the right knowledge –
an entire telegraphic network could have been constructed in the stone age.
Now our suited friend only has to wait for another stone-ager to create a second telegraph so he has someone to communicate with. Perhaps smoke signs would have been a better plan? Anyhow it is comforting to see that the presence of human knowledge and skill is more decisive than the existence of manufacturing infrastructure.