Generally speaking, scores at age 3 are not exactly inflated, but rather unstable, meaning that the likelihood that a re-test five or six years later will result in the same score is not as high as if the child were tested at age 8 and 13. They could go either way.
Yes, the test was standardized on children his age, and his norm-referenced scores will be derived from the performance of the age-matched comparison group, which likely had the same low level of tolerance.
However, did the entire evaluation consist of the DAS-II, or were there other assessments? Because 5 hours, even with breaks, is a really long time to complete the DAS, especially at age 3, and even in a suspected gifted kid. A more typical testing time for the DAS alone is about an hour, or less. Maybe an additional half hour, if you do all the non-core subtests. I'm guessing she did something in addition to the DAS-II, like achievement testing, or maybe some out-of-level testing, which may or may not generate standard/T scores.
