It IS about the tech level, but it is also about the roll of the dice. Sometimes the simplest solutions, mixed by masters, blow up (or don't get made at all?) while the trickier, more potent potions are made with ease by trainees. I'm pretty sure the blowing up is a RANDOM event, made less frequent only by upgrading the alchemy level. I still haven't purchased level 3 alchemy, but I rarely make potions anymore. When I have lab accidents, I just keep trying and make the extra healing potions between to help the recovery of my victims.
miskinsincap - the funniest is watching the elderly "run" from the lab. Everyone else has settled down and gone back to work while they are still making their "escape" out the ENTRANCE of the lab! I've learned to put the elders in the bath before mixing up potions, just in case. LOVE watching them do the back float!