原話是："The customized data are deliverable and .....so it will be owned by xxx(means us) without question."
The actual one is "If the customized data are deliverable .....so it will be owned by xxx without question."
The difference is the addition of "if".
It seems that you wanted to be more specific, hold them accountable.
Your boss wanted to be more flexiable, adding a leeway to drift in scenarios where the promised deliveries are at risk.
Thus, you and your boss have the different objectives in handliing the unexpected. To me that there seem more intrisic business interests under surface. You need get aligned with 1) the o*****ectives, 2) accountablities.
You might use the legal documents or contracts your company used in the previous cases business cases, or the endorsements from your legal departments/third party suggestions to persuade your boss.
