Maybe it was just another soul? Since 704 is a reaper the guy may have been a soul he was taking to the underworld or something, he probably confused San for a soul too, I’m not sure tho I got a bit confused during that last panel.
Yeah that must be it , we’ll see I guess..
thank you for your answer anyway ^^
the guy next to 704 is just another reaper. We see him with yama http://www.mangago.me/read-manga/fate_makes_no_mistakes/nto/ibx_chapter-53/pg-1/
He's probably scared either cos he's in a room full of scary/powerfull people OR they just found out San is actually human, and they made a mistake.
Who was the guy standing beside 704 at the end of the chapter ?