Is it permissible to challenge the opposition in the administrative decisions in absentia that appoint an expert?
Yes, Administrative Law decisions can be challenged on several different basis which do not always require an expert. I will try to lay these out for you in an easy to understand way.
A. Statutory Interpretation Section 706 of the APA directs reviewing courts to hold unlawful agency action “not in accordance with law,” 5 U.S.C.A. § 706(2)(A), and agency action “in excess of statutory jurisdiction, authority, limitations, or short of statutory right,” id. § 706(2)(C).
a. Chevron Deference In Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984), the Court suggested that reviewing courts should be deferential to agency-issued rules. When the meaning of a statute is unclear, a reasonable interpretation is entitled to deference.
B. Substantive Decisions Section 706 provides that a “reviewing court shall … hold unlawful and set aside agency action, findings, and conclusions found to be—(A) arbitrary, capricious, an abuse of discretion or not otherwise in accordance with law; … [and] (E) unsupported by substantial evidence in a case subject to sections 556 and 557 of this title.…” 5 U.S.C.A. § 6706.
a) Scope of Review Section 706 applies the “substantial evidence” test when agencies must create rules using formal procedures (trial-type procedures) under APA sections 556–557. By contrast, when an agency proceeds by informal procedures (notice and comment), the APA mandates application of the “arbitrary and capricious” standard. However, in some cases, Congress imposes a different standard of review.
i. “Substantial Evidence” Defined- The “substantial evidence” standard basically focuses on whether the record contains “such evidence as a reasonable mind might accept as adequate to support a conclusion.”
ii. “Arbitrary and Capricious” Defined- As the name suggests, the “arbitrary and capricious” standard requires courts to be deferential to agency action. Many believe that, in practice, there is little difference between the “arbitrary and capricious” and “substantial evidence” standards.
* In recent years, some courts have applied the arbitrary and capricious standard by inquiring whether there are “adequate reasons” supporting the agency’s choices. At times this review has been searching, while at other times the review has been more deferential
So in short, there are two different ways to challenge a decision made by an Administrative Agency, and they do not always require an expert to be retained.