How to return to academia after "don't walk, run"?
“Don’t walk, run” is a shorthand for taking immediate action to extricate oneself from a rapidly deteriorating situation. 

Note that this may not require leaving academia altogether, or even one’s current institution. You may be able to find a workable solution where you are by switching projects, advisors, or departments, as appropriate. 

But sometimes it is necessary to leave, for economic, personal, or medical reasons. You may want to return. In that case, it’s not really all that different from other cases. The critical step is explaining to whom ever you’d like to hire or admit you that whatever situation caused your previous departure will not affect the present situation. You’ll need to make that case clearly and convincingly so as to reduce the “risk level” of your potential boss. If you can’t make that case, then you may want to reevaluate if returning is the right move at the present time.