I believe he cooked his data, but it was the 1850s, and science was still along these lines:

Watson, do you think a monkey falling out of a tree falls slower or faster than one blown out of a tree with 00 buckshot?

I do say, Alfred, what an intriguing idea. I’ll grab the shotgun and you find a rock. We will meet back here in 15 minutes and find two monkeys.

15 minutes later
Alright, on the count of three, you throw the rock at your money and I’ll pull my trigger

But it’s going to take time for the rock to get there - your shotgun is instant

Fine you throw on two, and I pull on three. Ready? One, two…

He also got hilariously lucky in what he was doing. It’s worth a read into the modern-day reproductions (no pun intended) of his work to see just how unlikely he was to get his results as fast as he did.

There is a German word for this: Erbsenzähler (pea counter), someone who is overly rigerous, exact or cheap.

Switched to melons

Why does this guy look like Doug Heffernan lol

Ok, now try with hawkweed.