Tried quenching a 1084 blade in canola oil instead of my usual Parks 50 and the edge cracked on me

Man, my buddy Dale had almost the same thing happen last fall. He grabbed canola on a whim for a 1095 hunter and the tip cracked on him before he even got it out of the oil. Turns out his canola was cold from sitting in the garage, so it was even slower than normal. He warmed it up to about 130 the next time and slowed his quench down even more, and it worked fine on a thicker blade but he still won't trust it on a thin edge. He keeps a bucket of Parks 50 now and only uses canola for stuff he doesn't care about.