There are 2 sources that I turn to when discussing this topic. One is “The Dictionary of R.E. Estate Appraisal”, 5th ed. (I believe that there is now a 6th, but, I have the 5th), Appraisal Institute. There “ALT” is defined as “A transaction between unrelated parties who are each acting in his or her own best interest.” Giving “flesh” to this, I highly recommend an article authored by Richard Heyn, SRA: https://www.aciweb.com/arms-length-transactions-market-value-and-related-parties/
As to the question at hand, by the fact alone that a property is REO, the status is irrelevant to answering the question as it is the relationship between the parties that matters.