The article addresses the issues raised by OP. You don't need to read the paywalled article since it just summarizes the statement by Reinhart & Rogoff which is available here [1]. Here is an archive of the actual article if you would prefer to read that [2].
So before the corrections the growth was -0.1 percent for debt levels over 90 percent. After their corrections the growth was 2.2 percent. And then they try to pretend that that doesn’t really change the main conclusion of their paper, which was that high debt levels destroy growth.