I use a slightly older version of the library (2.30.2), so this might have been changed, but in this version there is no null check when using the indexing operator,

So this throws a null pointer exception:

array<int>@ arr = null;
arr.length();

But this does not:

array<int>@ arr = null;
arr[0];

This has already been fixed in the latest 2.31.1 WIP version that you can from the SVN repository.