We had added assertions that a participant who acted as a sub-router would fail a commit or prepare request if it hadn't heard back from any participants it had added to the transaction. However, it's not required that a cursor be exhausted before committing a transaction, and so it's possible to commit before a participant has heard back from every participant it added. These added participants will still be involved in the commit protocol, because the participant who acted as a sub-router will still inform the parent router of them regardless of whether they have responded.