How did this resolve?
References are not always checked. You could also use a former colleague or former student for a reference. If I were checking, I would optimally want references from a former boss, a peer, and a former student.
The kinds of things a reference for a teacher would be expected to talk about might be:
-How well did the teacher interact with students? Was the teacher approachable and have a good attitude toward learning?
-Did the teacher plan their own lessons or deliver premade ones?
-Were there any complaints about the teacher from students? (this is not a deal breaker, but it would give you an idea of the person's character)
-Was the teacher dependable? Did they show up consistently for work?