The case of Irwin v. Wright, County Treasurer of Maricopa County, State of Arizona et al., 1921 revolved around a dispute over land ownership in the state of Arizona. The plaintiff, Mr. Irwin claimed that he had purchased certain lands from the defendant's predecessor and paid taxes on them for several years before discovering they were part of an Indian reservation and not subject to taxation or sale by the county treasurer at all. He sought reimbursement for these tax payments arguing that it was unjust enrichment on part of the defendants as they collected taxes on property which wasn't theirs to sell or tax in first place. However, his claim was rejected by both lower courts and eventually reached Supreme Court where it was held that even though there may have been some mistake initially regarding status/ownership rights over said lands; once Mr.Irwin discovered this error but continued paying taxes without protest - he effectively waived any right to seek refund later as per principles laid down under doctrine known as 'voluntary payment rule'. This rule essentially states that if someone voluntarily pays something with full knowledge & understanding about facts/circumstances then they cannot demand its return later citing ignorance/mistake etc.

The dissenting opinion in the case of Irwin v. Wright, County Treasurer of Maricopa County, State of Arizona et al., 1921 was not available online for review and summarization. The details about this specific court case are limited and do not provide enough information to summarize a dissenting opinion accurately.