Just before Candy throws the ashtray at Dan, an open pack of matches on the table top disappears and reappears between shots.
At the end of the movie, Dan's bandage changes color between shots.
At about 50 minutes in, when Dan is writing down Roger's PIN, the viewer can tell see him writing small numbers in the corner of a piece of paper. When he is using the ATM, the numbers are very large, covering most of the width of the paper, and centered in that width.
The trailer for "Candy" has the following caption: "When love breaks all boundries." This is a misspelling of "boundaries."
Heath Ledger's character looks strung out most of the movie, Abbie Cornish's character looks like she could be going to a modeling gig.
When Dan is sitting in the shower, the tattoo (which was real and was blacked out for some reason - it is actually a cluster of planets) on his shoulder smudges and transfers to the shower tile. The next scene it is intact.
The copyright statement "Ownership of this motion picture is protected by copyright and other applicable laws, and any unauthorized duplication, distribution or exhibition of this motion picture could result in criminal prosecution as well as civil liability" appears to times back-to-back at the end of the end credits.
When Dan calls Roger to try to get his pin number for his bank account, he asks him his date of birth. Roger says it is 3rd May 1977, but when we later see what Dan has written down it reads 3rd May 1973.
When the bank teller is counting out the money, the notes aren't in any kind of order. In reality notes would be counted from the highest note down to the lowest.