According to
https://registrar.mcmaster.ca /serv...script-legend/, and my own experiences in undergrad, the fact that one grade was less than A- doesn't matter at all; it's the GPA that matters.
That said, I believe the assessment that determines Deans Honour List, etc., is made after the winter term, not the fall term.
So you'd have to maintain the 9.5 GPA at the end of this term (and, according to the link above, complete 30 units).