The UAF study suggests a free-fall drop of the building's interior during the collapse of WTC 7. NIST's explanation focuses on progressive structural failure due to fire-induced thermal expansion. The question of which explanation is more plausible depends on one's interpretation of the available evidence and is a subject of debate within the scientific community.
Based on the principle that a free-fall symmetrical collapse is typically inconsistent with asymmetrical damage, the explanation provided by the UAF study may be seen as more plausible to some individuals. However, it's important to recognize that this is a topic of debate within the scientific community, and differing viewpoints exist on the cause of the collapse of WTC 7.