Sheedy admits he would not have taken the kick if Halfpenny had still been on the field at the end, with the full-back replaced after 58 minutes in his first Cardiff game for 4,347 days.
“I would have had a great view of Leigh winning the game, which would have been just as special,” Sheedy admitted.
Sheedy praised Halfpenny’s influence since he arrived at Cardiff at the beginning of the season to take up a player-coach role with responsibility for kicking.
“I’ve worked hard with Leigh since he has come in,” the Cardiff-born outside-half added.
“It’s been unbelievable to be able to work alongside him. People pay a lot of money to go and watch Leigh kick and I get to do it as a job.
“I feel privileged to be able to learn from someone as unbelievable as him.”
Sheedy says Halfpenny has not tried to change too much but has provided invaluable advice.
“He’s very good,” said Sheedy.
“I remember the first time we had a chat about kicking and he was saying he’s not coming in to change me or how any of us kick, because we all have our different styles.
“It’s if we wanted to lean on him in any way.”
Sheedy was impressed by Halfpenny’s expertise.
“What I found with Leigh is he could watch a kick and would know exactly what was right or wrong,” he added.
“Something technical like when you’re opening up too early or you’re closing off with your kick.
“Something we wouldn’t know, he’s just got an eye for it. You can tell he’s been top of the game for 17 years, even if you just look at what he does in the week.
“The visualisation he does and how professional he is with the preparation he does for each session.
“It’s eye-opening for me and I’m 30. So someone younger will be taking so much from him.”