My quote still stands. Every major military did, and does, use spies to determine their enemies' and potential enemies' states of readiness/technology. The Japanese had outstanding engineers and pilots. The Zero was a wholly indigenous design. Western claims to the contrary are based in nationalism and racism which were rampant in their pre-war military planning. The fact it used published engineering technology/concepts/data (NACA et al) of the times along with a different design philosophy (armor/weight/maneuverability/range) than those of the West has nothing to do with the OP. The H1 had no more in common with the Zero than it did with the Fw 190 or P-36. It was not accepted by the USAAC as it was a lightweight racer with no potential to expand as a pursuit or interceptor AC. Thin wings, long thin gear, extreme aft cockpit = great racer design, terrible fighter design. Hughes was a narcissist in the extreme and any claims by him beyond the generic layout that his aircraft led to the Zero fighter are ridiculous.
Wikipedia: "Aviation writer William Wraga asserts that the H-1 Racer inspired later radial engine fighters such as the Republic P-47 Thunderbolt, the Mitsubishi A6M Zero and the Focke-Wulf Fw 190, without offering any arguments for that being the case"
And
"What Hughes actually asserted was that it seemed to him plain from examination of the two that the Zero was substantially a copy. An aside from Bill Utley, the Hughes company publicist, noted that one Al Ludwick had given details of pre-war inspection of the H-1 by Japanese generals at a New Jersey hangar. No actual evidence of copying beyond similarity of design is offered otherwise."