I think in that is used in place of because.

i.e if you want to state a reason 'in that' is followed by that reason.

Hi,
There is a difference between 'in that' and 'because'. I have come across this in one of Ron's posts and saved it in my document.

usage of 'in that' vs 'because'.
'in that' is EXPLANATORY and LIMITING. in other words, it explains the sense in which the immediately preceding description is used (explanatory), and it specifically implies no more than that sense (limiting).

example:
my approach differs from yours in that i am more aggressive.
--> explanatory: the difference in aggressiveness is the way in which our approaches differ
--> limiting: there are no other significant differences between our approaches

--

'because', as you say, shows a cause-effect relationship.

example:
my approach differs from yours because i am more aggressive.
--> there could be all sorts of differences between our approaches - some of which may have no direct connection to aggressiveness - but the ultimatesource or cause of those differences is the difference in aggressiveness.