If there's nothing significant going on between your head and your feet, there's nothing significant between your head and an "external observer" two metres above your head.

Say Anne is falling in behind you, and she either decides to "back out at the last minute" or just keep falling with you. As you fall, time is passing more or less the same for the both of you, so we can just go by your clock: You cross the event horizon at t=0, she makes her decision at t=1, and she either crosses at t=2 or doesn't cross at all.

Now, if Anne "backs out", her clock does diverge sharply from yours as she stops her fall and accelerates away from the event horizon, but this clock divergence happens after you've crossed the event horizon, not as you cross it or before.