What is the test for withdrawal of a deemed admission?

The plaintiff says that the test for withdrawal of an admission was summarized by former Master Horn in the case of Hamilton v. Ahmed, [1999] B.C.J. No. 311, the test being: Is there a triable issue which in the interests of justice should be resolved on the merits and not disposed of by deemed admission? In applying the test, all of the circumstances should be taken into account including: 1. That the admission has been made inadvertently, hastily, or without knowledge of the facts. 2. That the fact admitted was not within the knowledge of the party making the admission. 3. That the fact admitted is not true. 4. That the fact admitted is one of mixed fact and law. 5. That the withdrawal of the admission would not prejudice a party. 6. That there has been no delay in applying to withdraw the admission.