Can district take positions not raised in response to hearing request

The short answer is yes, they probably can. At least in New York State where SRO Paul Kelly holds court. But, in SRO 08-145, the parent argued that the district should be foreclosed from arguing the inadequacy of the parent’s notice of intent to seek reimbursement because the district had not raised this argument in their response to the hearing request. Kelly left open the possibility of holding for the parent in the future on this issue by stating

The parents argue that the district did not properly raise the issue of whether the parents
provided notice under 20 U.S.C. § 1412(a)(10)(C)(iii)(I) because it was not raised in the district's
response to the parents' due process complaint notice (see 8 NYCRR 200.5[i][4][i]). However,
the hearing record shows and the parents admit in their petition (Pet. ¶¶ 26-27, 30, 46), that at the impartial hearing the district's counsel cross-examined the student's mother on this issue and the parents did not object to that line of questioning (Tr. pp. 124-25). Furthermore, the district's
counsel reiterated this argument during closing statements (Tr. pp. 147-48) and the impartial
hearing officer appropriately made a determination on the issue.