This is quite untrue.
I believe there’s no hard and fast rule to writing and passing bar finals. You can write sparingly and pass. You can also be exhaustive and still pass.
For me, I recall writing a page and half answer for a sub question in Property Law…
In Law school, if you write one paragraph, that's first class. If you move to the second paragraph, that's second class upper. If you move again to the third paragraph, that's second class lower. Fourth paragraph Is pass and fifth paragraph is failure - Mr Udemezue