You are just going to have to go back and retrace your steps.... It either came out of the bag when you went down (one of those times), or when you grabbed out your second knife.... YOU CAN DO THIS....

My crew and I were chopping line through a crotch deep swamp of muck and mire and in the middle of a rest / water break ... after a bit we got into a cat tail fight (throwing cat tails at each other through the weeds for a few minutes) .... and one of my men lost his glasses in the swamp ducking a cat tail.... we could not find them and it was getting late and it was about 2 miles back to the truck...we had to get out of the swamp before it got to dark...the gators play about that time...we just happened to get a chance to go back about a month later... I walked out into the muck and mire and knowing the general area he lost them, and after looking around for about 15 minutes... I spotted the ear piece sticking out of some floating weeds....and found those glasses....

moral is.... go back and look....you can find your knife..it is a mission...

but check your car, pack, and clothing real well first

Good Luck

Doc