There is certainly no onus on the Land Registry to check whether the terms of a partnership/property agreement deed, which may have a bearing on an agreement between the parties, remains binding. Indeed, it is unlikely that the deed in question was ever sent to or required by the Land Registry.
However, if others believe a property registration is incorrect - if for example, it was based on apparently false evidence, they can seek to have it rectified.
On receiving an application for rectification, the Land Registry will serve notice on the other party that the application has been received and invite their comments. If comments are not received or if the issue is conceded, the rectification will be made.
If the issue is contested, the Land Registry must refer the case to the independent Land Registry Adjudicator. The adjudicator will usually hold a hearing to determine the outcome but also has the power to direct one of the parties to commence court proceedings instead.
Once the issue has been resolved, the Land Registry will update the register accordingly.