That route was probably my first climb, back, circa 1974. I had a spiffy new MSR yellow perlon climbing rope, rated at an impressive one fall!
Midway into what may have been the first pitch, I pulled off a fair sized rock, not quite of the size of your rockery de construction. But it chopped that new rope almost completely into two pieces. We retreated, to climb another day.....
I quit climbing way too long ago, but have been a practising arborist for 40 years now. I visit this forum now and then, but just joined, to reply and describe my similar adventure.