SourceTree hangs for a long time on large diffs

SourceTree hangs for a long time on large diffs. The UI is totally unresponsive. This shouldn't happen; it's better to bail out on large diffs rather than stop working for a minute.

Steps to reproduce:
1. Add the uncompressed Angular 1.2.0 file (available at https://code.angularjs.org/1.2.0/angular.js) to your Git, commit it
2. Swap Angular 1.2.0 for Angular 1.3.0 (from https://code.angularjs.org/1.3.0/angular.js); don't change the file size; commit it.
3. Click on the commit; at that point the UI freezes trying to display the diff.

After some time the diff gets displayed and UI starts working again. But if I do anything to this diff, e.g. scroll just a little, I get another freeze.

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Update: The workaround suggested below has seen positive results.