@c9202e22 FWIW, messing with this in JSFiddle on Safari actually *does* cause it to toggle+load there as well, just nondeterministically. So there might be something a bit more cross-browser going on. 

 @c9202e22 okay this works but I really hate it and do not understand what is going on with the change to the checked value during the native onclick handler: https://jsfiddle.net/cw8en4pt/ 

 @c9202e22 (tested on macOS safari, chrome, firefox) 

 @c9202e22 oh, ugh, looking elsewhere in the thread I see you want the link to otherwise keep working, please disregard. 

 @c9202e22 OK, the technique does basically still work.  Here you go; clean version with no debug prints, clicking the link goes to the link, clicking the checkbox toggles the checkbox: https://jsfiddle.net/980Lztxa/