OPINION
PER CURIAM.1, A police officer arrested Thomas Brown for driving while intoxicated, handcuffed him, and took him to a police substation for processing. The officer then administered a chemical breath test which showed Brown's blood-alcohol level to be .109 percent, in excess of the legal limit of .10 percent.1 The police officer informed Brown that he was entitled to an independent chemical test of his breath or blood. Brown declined to seek an independent test, but he insisted that he did so only because the handcuffs were hurting him and he wanted them removed right away. The police officer revoked Brown's driver's license based on the results of the breath test.
2. Brown sought an administrative hearing to review the revocation of his license. The hearing officer denied Brown's request that the hearing be held in-person. At the outset of the hearing, Brown objected on the grounds that a telephone hearing "hinders our ability to present our case." This objection was overruled. After holding a telephone hearing, the hearing officer concluded that Brown had knowingly and voluntarily waived his right to an independent alcohol test, and the hearing officer upheld a one-year revocation of Brown's license. The superior court affirmed.
3. On appeal to this court, Brown argues that he did not voluntarily waive his right to an independent blood test and that the Division of Motor Vehicles violated his due process rights by conducting the hearing tele-phonically.
4. We review directly the factual determinations of the administrative agency under the substantial evidence test,2 deciding whether "the findings are supported by such evidence as a reasonable mind might accept as adequate to support a conclusion."3 We review questions of constitutional interpretation de novo.4
*5885. Recently, in Whitesides v. State, Department of Public Safety, Division of Motor Vehicles, we held that the hearing officer may not deny an in-person hearing in driver's license revocation proceedings in cases that involve issues of the licensee's credibility.5 This case involves contested issues of fact as to whether Brown voluntarily waived his right to an independent blood test. Therefore, Brown was entitled to an in-person hearing.
6. Based on Whitesides, we VACATE the revocation of Brown's license and REMAND for an in-person hearing.
CARPENETI, Justice, with whom EASTAUGH, Justice, joins, dissenting.
EASTAUGH, Justice, dissenting.
. See AS 28.35.030(a)(2).
. See Handley v. State, Dep't of Revenue, 838 P.2d 1231, 1233 (Alaska 1992).
. Borrego v. State, Dep't of Pub. Safety, 815 P.2d 360, 363 (Alaska 1991) (citation omitted).
. See Walker v. Walker, 960 P.2d 620, 622 (Alaska 1998).
. 20 P.3d 1130, Op. No. 5388, 2001 WL 366621 (Alaska, April 13, 2001).