Headscratchers / Ten Miles of Peach Blossoms

• There were guards posted at Zhuxian Terrace when Su Jin took Su Su there and framed her. Aside from the fact these guards could attest to this situation (Su Su notably froze and Su Jin kept saying 'come on', Nai Nai protesting that it was not right instead of Xin Nu being unhappy), they are mysteriously absent when Su Su goes there to jump off. Shouldn't they have stopped her from going up, questioned why she was going, or had someone rush off to tell the crown prince his wife was there? The Emperor can't have known that was the day Su Su would jump and conveniently had them removed... or were the guards on the day Su Jin's frame job a set up to begin with?