1] I saw in the sefer Ishei Yisrael [at the end page תשלא] that Rav Chaim Knievsky Shlita says that in extenuating circumstances one may step back diagonally if the person behind him is davening [unlike what I wrote there so I was wrong].
2] My beloved friend Reb Yaakov Dov Ben Dovid Hakohen asked if one is allowed to learn while waiting for the person behind him to finish even though he [the one waiting] hasn't stepped back his three steps.
I remembered seeing in a sefer a long time ago that R' Chaim ruled that it is permitted to learn [albeit not verbally] but I couldn't remember where I saw it. A computer search revealed that the source is the sefer מעשה איש חלק ב' עמ' צו.
G-d bless the Otzar Hachochma program and it's creators and disseminators!
