What if it was a male teacher having sex with a 16-year-old girl student? Would that also be OK with you?
Or a male teacher having sex with a 16-year-old boy student?
Or a male teacher having sex with a 16-year-old boy student?
The abuse of the power differential should invoke professional termination, but the age clearly denies childhood status and there should be no criminal charges whatsoever.
Those would be different. However, that is not what happened in this case. This case seems subjectively to bend the rules of symmetry a bit.