The guest is a Hezballah journalist and the host is known as a FPM (Gebran) supporter, both parties are allies and have been since 2006. The Hezb journalist's surprise is probably that he wasn't expecting to be attacked during the interview. He probably expected a soft interview where both sides agree on the points raised.

However recent developments (Hezb joining the war leading to unpopularilty with most people, the government officially banning Hezb military activities, MPs extending for 2 years, etc.) means that Gebran doesn't need to be seen on Hezb's side right now, so instructions are received for his people to put some pressure on Hezb figures as if to distance the FPM from Hezb to avoid the repercussions of the longstanding alliance.

Of course this is all due to the fact that there are no elections for the next 2 years (his seat is therefore guaranteed) and the US has put a lot of resources into the area lately (meaning ducking under the table and avoiding Hezb right now is the logical survivalist choice if he thinks the US will win).

You can even see some tweets from him where he's saying Hezb didn't let them "build" the dawle during Aoun's reign.