I wonder why she wasn’t using a glove box - big thick gloves and proper venting.
My father was twice poisoned by mercuric chloride in a lab - contributed to mental illness that led to his death.
Both the original story and the Wikipedia article said she was working with the methyl-Hg inside a fume hood.
The original article said she was double-gloved and that the spill was so tiny she didn't even notice it. The Wiki article walks that back a bit, saying she was in contact with 'several drops' and was protected only by "latex."
She used methyl-Hg all the time, and had been using it frequently for years. It is apparantly a very good molecule for calibrating NMR equipment, having a clear strong isolated resonance at a frequency close to that of the cadmium atoms she was studying.
Maybe she got too familiar with the procedure. Maybe she was in a hurry, or distracted by something.
When you're working with methyl-Hg, there is no margin for error. You're dancing with death at all times it's in your hands, or even near you. It's just as dangerous as a test tube full of Ebola virus, except that it's not contagious. Or not as contagious anyway. It can't reproduce and spread.
The original article said it's a colorless, odorless, clear liquid. Looks like water.