What is the ruling when the buyer and the original owner (Shufi') disagree regarding ownership of improvements (trees or buildings) on a share of property acquired through pre-emption?

Primary text

If the buyer claims to have newly introduced the improvements (al-gharas wa al-bina') on the share, and the pre-emptor (al-Shufi') denies this, the statement of the buyer is upheld. This is because the buyer is the established owner of the share, and the pre-emptor seeks to gain ownership of that share including the improvements, thus placing the burden of proof on the claimant against the current owner.