The mistake

Legolas tells a story. (Based on another well-known lateral thinking puzzle).

“Guilin was a hunter of great renown,” said Legolas, taking a sip of wine. “Orcs, wargs, trolls—there was nothing he could not stalk—his hand was as swift as summer lightning, his aim as true as a dwarven blade.”

“Why do I get the feeling that this dwarven blade is about to let him down?” asked Gimli.

“Something to do with the past tense,” replied Eomer, cutting a chunk of meat and raising to his mouth on his knife.

“One fine winter’s day,” said Legolas, “tracking goblins across the misty mountains, he spotted a wounded she-wolf. She was dragging herself across the snow, her shattered hind-quarters leaving a terrible red stain—”

“Lassui! We are eating!” Eowyn refilled his glass.

“Guilin could not bear to leave her suffering. So he raised his bow, took careful aim, and shot her between the eyes. She died instantly. But seconds later, he realised his mistake. And minutes later, he was dead.” Legolas took another sip of wine.

“How?” asked Eomer.