Well elephants did. Namely Tusko after 300mg of LSD.
Considering that the active dose is about 20-30 MICRO-grams, then basically you're saying that someone can die if they exceed the active dose by literally 10,000 TIMES. As in a million percent. Literally.
While that's, of course, good to know, that would still make it incredibly safer than a lot of stuff that is legal.
By comparison you get about 1mg of nicotine absorbed per cigarette, and the LD50 (50-50 chance to live or die) for an adult human is 40-60mg. So about 40-60 active doses can kill you. Stone dead.
Plus, if someone's going to exercise as little judgment as to take 10,000 doses of LSD, you need to be even less stupid than that to kill yourself with cigarettes. You just need to eat a pack of cigarettes to kill yourself. Most of the nicotine is actually burned while smoking the cigarettes, so you get IIRC about a tenth of it. Eat a pack and you've just taken in some 200mg or more.
As another comparison, for alcohol you get tipsy and euphoric anywhere between 20 and 100 mg/dL, and death by respiratory failure occurs around 400mg/dL. So you can only exceed the dose to get mildly buzzed by 4 to 10 times before you die. And I'm not talking the dose to be drunk off your ass, which would be a more apt comparison to what those 30 micrograms of LSD do to one, in which case you might have as little as 50% margin before you kick the bucket.
As another comparison, for caffeine the LD50 is estimated at about 150 to 200 milligrams per kilogram of body mass. Which does mean about 80 to 100 coffee cups for an adult, but again, it just shows that between what passes for an active dose and what kills you, you only have an about 100 times difference. And while it's hard to do with brewed coffee, you CAN kill yourself with caffeine pills or powder, and I remember at least one case where someone took a bunch of caffeine and washed it down with an energy drink, and promptly kicked the bucket. So, again, if someone was determined to try 10,000 doses like with the LSD comparison, they'd kick the bucket about 1% into it with caffeine.
Basically I'll gladly concede the point that you can kill yourself with too much of anything, including LSD, and even including water. But, you know, it still would make LSD incredibly safer than a lot of other things which are legal, freely available and don't even need a prescription.