Board Thread:Manga/@comment-37302341-20181025210640/@comment-1327106-20181026021440

Floch was guarding Yelena, not Eren. There were no issues letting Eren run around doing things at that point in the story, but Yelena wanted to appear clear of suspicion so she voluntarily put herself under guard and Pixis notes that Floch changed after being assigned to that position.

Looking at the wiki article in question, I think whoever wrote that section was working off a fan translation and I'm going to correct the article in a moment as none of that appears in the official translation.

Edit: And fixed.