In the 16 years I have been here I have never seen this matter arise. The member is correct in citing Standing Order 44(1). It is a provision I was not aware of, and I doubt very many people on the government side were aware of it either. It says "except in explanation of a material part of his or her speech".
The question is a good one. I do not see any requirement for unanimous consent for a member to explain some matter of his speech. I will be happy to hear from all members who wish to speak to this.