jump the gun

Oct.27のJapan Times Onlineにあった記事タイトルと見出しです。
Strolling old Fukagawa, where gardens and true glitterati mingle
I may be jumping the gun a bit on fall colors, but early October's glorious weather has got me craving some autumnal arboreality.
慣用句の参考書か何かに "jump the gun" の表現が出ていた記憶がありますが、実際の文で使われているのを見るのは初めてです。この際にしっかりと覚えて置きたいと思います。辞書の説明を引用します。
・Collins Dictionary:
1.(of a runner, etc) to set off before the starting signal is given
2.(informal) to act prematurely: But it means that she's not prepared to jump the gun in any way.
・Cambridge English Dictionary: to do something too soon, especially without thinking carefully about it: They've only just met - isn't it jumping the gun to be talking about marriage already?
・McGraw-Hill Dictionary of American Idioms and Phrasal Verbs: Fig. to start before the starting signal. (Originally used in sports contests that are started by firing a gun.) We all had to start the race again because Jane jumped the gun. When we took the test, Tom jumped the gun and started early.
フライングと言うのは和製英語ですかね？