I never got to check mine last weekend, trying again today, has been 4 weeks since the fence came down.
I do think there is some left over fear of the fence, but I also think two other things come into play.
1. The field probably has 20+ times more forage than young unprotected beans do, so they eat more up up and down the plants in a smaller area, where the same browsing would wipe out much a larger surface area if just young young beans. i.e. the field can withstand 20+ times more browsing now than if left unprotected.
2. Young tender beans are preferred over more mature larger leaf beans.
My plot would be wiped out in 2-3 weeks without protection, last year after I took the fence down, 30% was never used. So I planted 6 weeks earlier and took the fence down 2-3 weeks earlier.