Yer friend the Climbing Ranger here.
By the way what was your near fatal mistake?
This week climbers would have needed to be extra speedy for their climbs on The Half Dome. Tuesday there were waterfalls streaming down the slabby side in at least 15 different flows by 5pm. Monday and Wednesday there was some rain/thunderstorms as well.
That’s too bad the Ranger you talked to didn't tell you that you can get a Wilderness permit for the Base of the "steep side" of Half Dome. (The first time I went up to do the RNWF I didn't know either...but that was before my days of green and grey.) If you go to the Permit Office ask for a wilderness permit for Little Yosemite Valley/Pass Thru...ie you are not staying in the campground above Nevada Falls...for the days you will be at Half Dome. Its free, and the young rangers at the Wild. Center let you know about conditions, and other pertinent info such as our favorite, da Bears.
Also Half Dome stands alone in the Valley as a wall you can actually legally bivy under (with a permit), and I think it would be wise for climbers to follow through with getting them before they take off. I already have had other Rangers ask me about Half Dome, and what to do with climbers who don't have permits. It would suck if one of them told you to hike back to the Valley Permit center before you blasted off. In light of recent reports of poop bags, garbage, and abandoned property as well as food left at the Base of HD I might expect more frequent Ranger patrols in the area.
Check out my next posting about a recent and pretty gnarly bear incident that I picked up at the base of Half Dome around the Direct NWF route. It involved chewed up soup cans, tuna cans, and the tastiest item of the little meal, WD-40. Mmmmm, I bet the bear had a little indigestion after that snack.