Maybe he meant motion sickness? Some people get motion sickness in some FPS (I know because I sometimes do ). And some are more susceptible than others. Endless Ocean is first person (albeit not a shooter), so I guess some people may get motion sickness from the game (?)
Currently Playing: Shin Megami Tensei: Devil Survivor Overclocked, Professor Layton and the Curious Village
Anticipating: Xenoblade, The Last Story, Mario Kart 7, Rayman Origins, Zelda SS, Crush3D, Tales of the Abyss 3DS, MGS:Snake Eater 3DS, RE:Revelations, Time Travellers, Professor Layton vs. Ace Attorney, Luigi's Mansion 2, MH TriG, DQ Monsters, Heroes of Ruin