The 33-year-old actor, who played nurse Toni Thompson in the soap opera, had to be rushed to Dunedin Hospital after her first day of rehearsal.
"Laura was slicing carrots for tea after rehearsal when she cut the top of her left thumb off," director David Lawrence said.
"There was a sizeable chunk of flesh on the chopping board. But it wasn't big enough for them to reattach."
Dunedin Hospital had only just recovered from a norovirus outbreak, which affected about 200 staff and patients at the Dunedin and Wakari hospitals.
"Her character on Shortland Street died of the same thing, which Laura thought was quite ironic," Lawrence said.
"The nurses recognised her at the hospital and made a real fuss over her. Apparently, they were quite impressed that she knew what all the different pieces of equipment were called."
Hill joined Shortland Street in 2001, before taking a sabbatical last year.
She returned to the show last December, only to find the writers had set her up for a dramatic car crash which would leave her with one kidney.
After contracting norovirus, she went into cardiac arrest and "died" on June 12, 2008.
