Anko Mitarashi saw that Gaara and his team had completed the Forest of Death without a single scrape or cut, and in record time, doing it quicker than any other team of Genin to have attempted the challenge. Gaara was matched against Rock Lee in the preliminary round of the Final Exam. Lee's incredible Taijutsu, strength, and speed allowed him to burst past Gaara's Sand barrier and finally travel so quickly that Gaara couldn't see him. This surprised both Gaara and his siblings since it was the first time he had been harmed by an adversary.
This has caused some consternation among Naruto fans since Gaara retains the skills he had when Shukaku was one with him. While it is never stated in the narrative, it is safe to presume that Gaara still possesses his sand abilities since he learnt how to manage and own them during the time Shukaku was combined with him. Ironically, Gaara becomes stronger over time after Shukaku is removed, as seen by his defeat and sealing of the Second Mizukage in the World War arc.
