In 1924, Oppenheimer was informed that he had been accepted into Christ's College, Cambridge. He wrote to Ernest Rutherford requesting permission to work at the Cavendish Laboratory. Bridgman provided Oppenheimer with a recommendation, which conceded that Oppenheimer's clumsiness in the laboratory made it apparent his forte was not experimental but rather theoretical physics. Rutherford was unimpressed, but Oppenheimer went to Cambridge in the hope of landing another offer. He was ultimately accepted by J. J. Thomson on condition that he complete a basic laboratory course. He developed an antagonistic relationship with his tutor, Patrick Blackett, who was only a few years his senior. While on vacation, as recalled by his friend Francis Fergusson, Oppenheimer once confessed that he had left an apple doused with noxious chemicals on Blackett's desk. While Fergusson's account is the only detailed version of this event, Oppenheimer's parents were alerted by the university authorities who considered placing him on probation, a fate prevented by his parents successfully lobbying the authorities.Oppenheimer was a tall, thin chain smoker, who often neglected to eat during periods of intense thought and concentration. Many of his friends described him as having self-destructive tendencies. A disturbing event occurred when he took a vacation from his studies in Cambridge to meet up with Fergusson in Paris. Fergusson noticed that Oppenheimer was not well. To help distract him from his depression, Fergusson told Oppenheimer that he (Fergusson) was to marry his girlfriend Frances Keeley. Oppenheimer did not take the news well. He jumped on Fergusson and tried to strangle him. Although Fergusson easily fended off the attack, the episode convinced him of Oppenheimer's deep psychological troubles. Throughout his life, Oppenheimer was plagued by periods of depression, and he once told his brother, "I need physics more than friends".In 1926, Oppenheimer left Cambridge for the University of Göttingen to study under Max Born. Göttingen was one of the world's leading centers for theoretical physics. Oppenheimer made friends who went on to great success, including Werner Heisenberg, Pascual Jordan, Wolfgang Pauli, Paul Dirac, Enrico Fermi and Edward Teller. He was known for being too enthusiastic in discussion, sometimes to the point of taking over seminar sessions. This irritated some of Born's other students so much that Maria Goeppert presented Born with a petition signed by herself and others threatening a boycott of the class unless he made Oppenheimer quiet down. Born left it out on his desk where Oppenheimer could read it, and it was effective without a word being said.He obtained his Doctor of Philosophy degree in March 1927 at age 23, supervised by Born. After the oral exam, James Franck, the professor administering, reportedly said, "I'm glad that's over. He was on the point of questioning me." Oppenheimer published more than a dozen papers at Göttingen, including many important contributions to the new field of quantum mechanics. He and Born published a famous paper on the Born–Oppenheimer approximation, which separates nuclear motion from electronic motion in the mathematical treatment of molecules, allowing nuclear motion to be neglected to simplify calculations. It remains his most cited work.

Question: What led Bridgman to believe Oppenheimer shouldn't be doing experimental physics?
Answer: Oppenheimer's clumsiness