Sergeant Howie: What religion can they possibly be learning jumping over bonfires?
Lord Summerisle: Parthenogenesis.
Sergeant Howie: What?
Lord Summerisle: Literally, as Miss Rose would doubtless say in her assiduous way, reproduction without sexual union.
Sergeant Howie: Oh, what is all this? I mean, you've got fake biology, fake religion... Sir, have these children never heard of Jesus?
Lord Summerisle: Himself the son of a virgin, impregnated, I believe, by a ghost.
Lord Summerisle: Do sit down, Sergeant. Shocks are so much better absorbed with the knees bent.
May Morrison: Can I do anything for you, Sergeant?
Sergeant Howie: No, I doubt it, seeing you're all raving mad.
Sergeant Howie: And what of the true God? Whose glory, churches and monasteries have been built on these islands for generations past? Now sir, what of him?
Lord Summerisle: He's dead. Can't complain, had his chance and in modern parlance, blew it.
Lord Summerisle: Come. It is time to keep your appointment with the Wicker Man.
Miss Rose: The building attached to the ground in which the body lies is no longer used for christian worship, so whether it is still a churchyard is debatable.
Daisy Pringle: The little old beetle goes 'round and 'round. Always the same way, y'see, until it ends up right up tight to the nail. Poor old thing.
Sergeant Howie: 'Poor old thing'? Then why in God's name do you do it, girl?
Sergeant Howie: You are despicable little liars.
May Morrison: You'll simply never understand the true nature of sacrifice.
Rowan Morrison: Did I do it right?
Lord Summerisle: You did it beautifully.
Answer: He would likely die from the heat or smoke inhalation long before the wood would deteriorate enough for him to fall out. The film also makes a point to show that Howie has given up trying to fight the villagers and has accepted his fate, so even if he could have forced his way out he no longer had the will to do so.
BaconIsMyBFF