First of all, the state needs to quit counting their scores towards the standardized testing grades. A mildly special ed student is required to take the same test as normal children. This forces teachers to slow down the curriculum until the slower students "get" the material, which can take some time.
I have a better one for you. How about the school district provide the supports the student needs to be successful in the classroom? You know, those pull out for pre-teaching, re-teaching? proper modification of curriculum and teaching methodologies so these students can actually learn?
The whole don't-you-dare-assess-me-based-on-the-slow-kids argument makes me want to vomit. A good teacher should and can teach, and motivate all levels. Those teachers aren't a myth, they work in my school district. A mildly special education student is more than capable of learning and staying grade equivalent.
NCLB Act brought accountability of teaching the student with special needs. Prior to that they were locked in the windowless classroom in the basement. All students can learn, and when they learn they become contributing members of society.
If that student fails the standardized testing, it reflects poorly on the teacher. They can't dock their pay, but they can (and do) move them to less desirable grade levels.
Well then this teacher should be advocating for services for that student then, or embrace differentiated instruction (which is supposed to be a requirement, but like everything else the US DOE mandates, it falls apart when theory meets practice because there is no real accountability so school districts punt the far majority of the time). A student with a disability who is not keeping up with the general curriculum should be on an IEP. The assessment (whatever that is in Texas) would (or should) then subgroup that student into that category. SpEd students are failing in Mrs. Johnson's class should then trigger further review as to what is missing --are accommodations appropriately being provided for testing/assessments, does this student require more services? etc. It shouldn't delegate the teacher to a less than desirable grade levels (whatever the hell that means).
Secondly, they need to quit putting ESL students into regular classrooms. Last year my wife got a kid (adoption from China) who didn't speak ANY English. Everything she taught had to go through a translator (in class, BIG distraction) and feedback had to be received the same way. Guess what? He had to take the same standardized test as the other kids.
ESL students are not special needs students, or they sure as hell shouldn't be designated that way. They have (or should have) their own subgroup of ESL. I bet you that student is fluent in English now, or pretty close to it. I am completely against the ESL substantially separate rooms, which a great deal of school districts keep those students in the entire time they are with them. Boggles the mind. Young children -- especially elementary age students -- are capable of picking up languages quickly. Peer modeling is certainly the quickest way to learn that skill.