Can multiple people learn the same spells at the same time from a teacher?
Apparently not, rules-wise.
Learning a spell from a teacher isn't at all like learning an ability: you are effectively reinventing the spell for yourself, in the laboratory, under the guidance of someone who knows it already.
If I were to allow a magus to so tutor multiple students, I would at least require rolls on the experimentation table.
Or maybe use the rule for multiple lab help? Ie. Leadership skill limits the number.
How aboud dividing your teaching lab total by the number of students?