LOL funny man ahha
I think it was an accident since after the 4th guy got stuck, marine 5th and 6th tried to go around but number 5 fell in as well.
I had personal similar experience myself on exercise during NSF days.
I was leading my platoon one night. Lead platoon ahead of the company. Night movement in Ulu Sembawang. Walking along a kampung track. Suddenly point man stopped and word was passed down that he suspect enemy ambush ahead. I went up to the point and indeed saw movement of enemy in the front at a junction. Decided to move back down the line and report to the OC.
In my excitement, I was doubling back , I fell into a BIG PIT in the middle of the track. How it got there, god knows ! Anyway, the worse was that it was raining during the day, the PIT was full of muddy sh...it ! This was of course in full view of No. 2 section , which was where they had taken cover nearby. I pulled my muddy self out of the pit... M 16 was all covered with gooey mud... I was covered in mud up to my waist. All around, I can see white teeth flashing in the night. The guys were having a good (silent ) laugh.
When I reported to the OC in my state, he also broke out laughing !