Yes, further down the T&Cs you find:

16.1.14. Subject to Clause 16.1.12, Awards can only be issued by British Airways to members of the Household Account (and will not be issued to persons that are not members of such an account), as designated/nominated by a Household Account member at the time of issuance, after which Awards may not be transferred or reissued to a different name.

And for the avoidance of doubt:

16.1. The following are the specific terms and conditions that apply to Household Accounts. If there is any conflict between the terms and conditions in this Clause 16 and any other clause herein, these terms and conditions will prevail to the extent the term or condition relates to, or regulates the operation of the Household Account:

You could consider adding the non-member to your HH account, or dissolvethe HH account (for six months minimum). The only quirk is that an Amex 241 voucher can be used to book the second ticket for a non HH-member.