When Inigo sees the scene inside, he realises that Senku's body indeed must have been moved. Just the way it's been laid out there, with the pelts and all, makes it pretty obvious that someone deliberately moved it and left it here like this - unless he fell asleep like this, but Senku's explanation makes it pretty clear that that wasn't the case.

He carefully takes a step closer to the statue, staring at it for a moment.

This sucks. The train interfering with worlds by randomly dragging people out of them, causing things to get worse in said worlds.. It really sucks, and Inigo feels a heavy feeling in his stomach that he's trying really hard to suppress. He doesn't want to throw a fit when he has to be strong for Senku.

"That must mean that people petrying can't have happened the moment you left." Because someone still moved his body.

Inigo's tone is on the serious side, but he's trying really hard to keep it from becoming too heavy as he speaks.

"Some time must have passed before it happened."

Hey, at least that's a step towards figuring out what exactly happened.