If you are a printer, sometimes, you can blame mistakes on someone else...
Take the above example, perhaps it was lack of concentration, maybe a little too much wine, or perhaps not enough sleep, I choose to blame it on 'Titivillus' or 'The printer's Devil'.
There are a couple of origins for these pesky demons.
TITIVILLUS was attributed to errors that crept into manuscripts of early scribes, and were said to be listening in to idle gossip that occurred during a church service - earmarking them to add to a list of souls to take to hell. He is said to be responsible for the errors of scribes when they copied and re-copied manuscripts, often leading to a complete change of scripture meaning throughout the ages.
Once printing presses and moveable type was mainstream, he was cursed for being responsible for letters being set and printed upside down, lines and words being missed completely.
THE PRINTER'S DEVIL l is basically the modern tile, incorporating the actual word 'printer' rather than a derivative of Latin titulus (“title, inscription”). The printer's devil was again blamed for all errors and print room 'Cock ups'* (*The accidental misalignment of text in a line of type)
A printer's devil was a popular title give to a printer's apprentice since he was charged with collecting lead type, cleaning black in off presses and working at the foundry where lead type was melted to produce new sets of type.
In the early days of printing (1400's) was associated with the dark/black arts - most likely by the scribes themselves when they could see that their high rank and social standing was to be eroded and replaced by the 'new' style of distributing the written word to the masses. You can imagine they were a tad miffed.