I think the trick with the ice chart and making the correct turn is that by time they reach this critical turn, the positions/formation of the chart data is already well over 24 hrs old. By then things shift around, openings may become less defined or gone altogether. Possibly new openings may have formed, as well.
Maybe the escape route was there, maybe not. I don't really know. I won't discount that it would be a precarious task to identify and navigate such a dated path in the dark of night. If it wasn't defined enough to acquire it visually at the predicted coordinates, that would still be quite an executive decision to turn right into the ice at the predicted spot on the hunch that a path should be there or may become more apparent once you drill in further. I'm not sure what decision I would make in those shoes.
Question is- for such a critical point in this operation, why didn't that ice chart guy make sure he was on the bridge at that time to help reassess the conditions? If he was asleep in his bunk, why didn't that old guy send to wake him once they reached that spot? I think they are both guilty of not doing all they could to exploit this opportunity.
I'm not sure we are presented in the show with clear enough information to say either way if the turn should have been taken. I think all of that drama was more about directing attention on that old guy as being a real luddite (whether he was truly right or wrong).
I need your sweet love, Rosetta Stone girl!