That sucks!
I have done the same thing but got lucky and got the stuff back.
My current practice is: Do not put any thing on the ground. Set rods on the hood or break em down and put in truck. If you do want to lean rod against the vehicle only do it at the drivers door so you have to move it to open.
Same with all other gear.
I have a bad case of CRS so I need to be extra vigilant.
When unloading drift boat after a day I walk around it twice to check for loose Items and tie downs before driving off.
Hope who ever finds it will want to return it and collect the good Karma.