I know perfectly well which there, their or they're to use ........but my typing fingers work faster than my brain sometimes and mistakes happen.
I'm a self confessed compulsive edit addict though, so when I notice, I change it quick, but I imagine some people may type the wrong one and just think sod it.....I don't think you can always assume they are unaware of the correct usage.
As for "pacific" I'm not sure I've seen anyone type that in error .....(I'd love to though!
).. but I know I find it damn hard to say "specific" in RL.
I have to pause to think it through before I say it, not because I don't know what it is..... but just because my mouth refuses to play along!
I have the same problem with "Statisitics" and it's one of the main reasons I gave up my childhood dream of being a Statistician.