In the middle of the section of the tochacha, in 26:23-24, Hashem says, "וְאִם-בְּאֵלֶּה--לֹא תִוָּסְרוּ, לִי; וַהֲלַכְתֶּם עִמִּי, קֶרִי. וְהָלַכְתִּי אַף-אֲנִי עִמָּכֶם, בְּקֶרִי; וְהִכֵּיתִי אֶתְכֶם גַּם-אָנִי" - and if despite all this you still walk with Me in happenstance, I will walk with you in happenstance and I will smite you...
That does not exactly sound like בקרי - happenstance. b'keri sounds like whatever happens happens. It does not seem like it should include "I will smite you". This sounds not b'keri, but against. So how does that last phrase fit with what Hashems says that he will go with us b'keri?
The natural result of Hashem not going with us full-time, is our being punished. We have only survived the generations because of Hashem's protection. If we stop doing the mitzvos, and subsequently Hashem stops offering us His portection, but goes with us b'keri, we will be hit.
We deserve to be hit, in that situation, and have no protection from Hashem. So, yes, being hit is a natural result of b'keri.