Did you miss that Rabbi Sorotzkin said that they are starving the kid? Are you accusing a Gadol B'Yisrael of lying?
I believe that it is factually correct. The context may be wrong though.
From the Israeli police perspective, if the partner is not being 100% open with them, for whatever reason, they are treating him like any other murder suspect would be treated inIsrael.
In Israel there is no real due process, this is just the way they do things when they need info.
From our POV the partner is obviously not a murderer, but he could be hiding something unrelated to this..... In the video it does not look like two good buddies going hiking. Something is missing..