>>43551885James Turner is an Englishman; he naturally is going to associate a Pokemon with its English name over its actual name and inspiration. James Turner was not employed at Game Freak at the time Bulbasaur was made, so he only has secondhand knowledge of the Pokemon like the rest of us even though he works at an official capacity in Game Freak currently.
Sugimori was the designer from the very beginning of the series. He was around when Bulbasaur was made, and in fact he was the primary designer of Pokemon iirc. Sugimori outright confirmed Bulbasaur was based on a frog.
