in case is understood in the same way by both British and American speakers.
You are correct that the use of
in case seems strange in the second sentence.
The first part (before
in case) involves making preparations, and the part that comes after
in case
is something you have no control over, something you can't
predict. (You have control over making spelling mistakes, so that
won't work.)
Note the pattern of
'preparation'
in case 'something unpredictable'
below:
While reading, you should keep a dictionary handy in case you see a word you don't know.
Take a sweater in case the weather turns cold before you return home this evening.
We'd better keep extra canned goods on hand in case there's an earthquake.
In addition to stocks, buy safer investments in case the value of stocks goes down.
Keep extra money in your savings account in case there's an emergency and you need money quickly.
CJ