Male behavior technician at ABA school

So this may be a controversial question because I know there are both mothers and fathers in this group. But my 4 year old/level 2/somewhat verbal son started an ABA therapy school In December. He’s been loving it so far and doing great there for the most part. He’s really liked his behavior technicians assigned to him. But today school informed me they changed his classroom and technician/teachers - one of which is a male. My husband is very adamant about no males being alone with our son or doing potty training with him. He is just strongly against it. He wants to call them and tell them to change it or we’re taking him out. I don’t want to burn our bridges with them so I’m wondering if anyone else has felt this way or dealt with this? Or are we crazy? He feels if anything were to happen my son can’t tell us about it. Any advice on how to approach it?