A person cannot step back after Mincha due to a guy davening behind him. However, the shul has already begun Maariv. Should the guy who is trapped daven in his place, all the way through SE, without taking steps backwards or forwards as is customary?
If it becomes possible to step back during Maariv, what should he do? He cannot say oseh shalom because of hefsek.
This is something that sometimes happens after Yom Kippur when someone is still davening neilah and the tzibbur already started maariv.
If he has to daven shemona esrei since he has to take the three steps forward, so he can rely on the opinion that he may walk out of being in front of the person davening in back of him. (This opinion holds that he only problem is to cut across him, but not to walk away from him if you are in front of him. We don’t usually use this opinion, however here we have to rely on it.) Therefore do take the three steps back (without saying oseh shalom), and then you can take three steps forward and daven shemona ersei somewhere else.
However if they only started borchu, he shouldn’t do that, but he should wait, and when the person finishes davening he will take the three steps back, without saying oseh shalom. (The main part is the three steps, not the words oseh shalom, which may not be said during birkas kriyas shema).