When Sweeney is shaving the Jailer right at the start of the program we see him shave his top lip clean, then it cuts to a close shot of Sweeney and back to the Jailer. His top lip now has a full layer of shaving foam.
Some of the "corpses" Todd is chopping up in his cellar are still breathing.
When Matthew is left on the steps after his death he opens his eyes right before the scene fades.
In the Church scene, the Lord's Prayer is being recited. The version that is used (beginning "Our Father, who art ...." was not in use until 1928. The only version that would have been used in Todd's time is that from the 1662 Book of Common Prayer, which begins "Our Father, which art ...", and differs in a number of other details.