Lack Of Knowledge Of Social Complexities

Anderson, Poul, "The Man Who Came Early" IN Knight, Damon, Ed., 100 Years Of Science Fiction (London, 1972), pp. 185-212.

Unable to support himself in tenth century Iceland, Gerald Robbins is insulted and must fight;
he wants to fight with fists but is obliged to fight to the death;
he kills a man with his gun so the Thing must decide between weregild and outlawry;
failing through ignorance to declare a manslaying at the first garth he seeks, he becomes immediately a murderer and an outlaw;
the slain man's father and brothers attack him till his gun gives out.

I would have known even less than Gerald and succumbed even sooner!

Even when dead, he receives some respect:

it is acknowledged that he defended himself well with a dead man's sword when his gun gave out;
for fear of the ghost, since he may have been a warlock, his body and everything that he had owned, even a valuable knife given as a present, are burned and a barrow erected but shunned.

Although Gerald's story of the world a thousand years hence refutes the priest's claim that the world will end soon, it seems that Gerald himself came from a time when the world might indeed end soon. Suddenly the great social differences between the two periods seem insignificant.