The Evils of Parts Libraries
Well, maybe "evil" is too strong of a word, but it sometimes seems fitting, given the amount of grief caused by parts libraries in CAD packages. Sometimes it's because the part isn't in the library. Sometimes it's because the solder paste stencil pattern would lead to poor soldering. Sometimes the part size is just wrong.
Here's a case where the part outline didn't quite match the package. The designer wanted to get bypass caps in as close to the BGA pins as is possible - that can be very important with many components these days, especially RF and high-speed parts.
Unfortunately, the part outline in the CAD library did not match the actual outline of the part. I don't know why. Maybe this is a functionally equivalent substitution from another manufacturer. In any case, it speaks to the value of verifying things like actual part dimensions before sending the board out for fab.
actual size may vary