- The Pirates of the Caribbean movies have always been set in an indeterminate 18th century setting (this one being around the 1760s), but the film has Jack Sparrow facing the guillotine (mentioned as a new addition and shown to have been used at least twice already) was invented in 1789 and first put into effect during The French Revolution. By this point, in the 1790s, the era of piracy was well and truly dead in any meaningful sense. Due to being called the guillotine by name and stated to be a new addition, it is unlikely to be based on the Halifax Gibbet of Halifax, West Yorkshire (disassembled in 1650) or the Scottish Maiden of Edinburgh (last used 1716), which were precursors to the guillotine (it is unknown if Dr. Guillotin was even familiar with either device).
- It's also far too late to have a womannote formally charged with witchcraft in an English court; while the belief remained much later, the last such case was in 1712 and was considered something of an embarrassment even then. It's also possible all the overt supernatural shenanigans could have caused a witch trial hysteria, however witchcraft had been decriminalised in 1735 and prosecutions moved into the vagrancy act (i.e. if you claimed you could do magic, you were a con artist) and even before then it was an offence of degrees that didn't always merit capital punishment. Hence it's really weird for a government official to push for a hanging (even with bloodthirsty mob) for someone who didn't actually harm anyone.
- Jack briefly mentions how the French invented mayonnaise, a 19th century invention, as he's being led to the guillotine. This was a Development Gag to a line Jack said in The Curse Of The Black Pearl note which was ironically cut because it was anachronistic.
- One of the pirates at the Shotgun Wedding plays Felix Mendelssohn's Wedding March on a makeshift violin (and it sounds dreadful). It was composed in 1842.
Anachronism Stew / Pirates of the Caribbean: Dead Men Tell No Tales