https://bugs.winehq.org/show_bug.cgi?id=8365
--- Comment #29 from Goblinstomper@gmail.com --- sorry about the spam, just realized that I didn't really answer "how". 1) Start the tutorial 2)proceed through the tutorial until they've instructed you to open the options menu 3) alt-tab (in my case: to a browser I can't see - then I pressed ctrl+t to open a new tab in the browser I can't see to make sure that the browser really has keyboard fokus) 4) press alt-tab in order to switch through all open windows to cycle through the game and the browser (in order to use the task-manager thumbnail to ensure that a new tab really was opened in step 3) keep going until game has focus again in the task manager. 5) Press O to open the options menu. Game should have (or well, at least did) have keyboard focus.
So, I guess it is possible that the prolonged alt-tab at step 4 fulfilled the same 'alt stuck' behavior you encountered?