That doesn't sound right. How could he be making effective progress at a 1.5 gl in gr. 4? What is his IQ? If he falls in the "gray area," of about 75-85, sometimes the formulas that are used make it impossible to qualify a kid.
So, he doesn't qualify for a self contained class, but what about resource/inclusion services? And how can this decision be made based on preliminary testing by the teacher? If a parent requests a sped eval, then by law, it has to be done, within 30 school days. A full evaluation. You should look for scores that compare his IQ to his achievement, i.e. WISC scores compared to Woodcock Johnson scores.
This is against the law. It doesn't sound right and wouldn't fly here or where I taught in AZ. One teacher does not get to make that decision!