N/A

I have seen case studies where people add back taxes and a variety of other cash flow items rather than subtract. Also where the person literally did not finish a single thing, like not even P&L.

Depends on how bad the line item is, and if it’s clear it was a mislink. For example, if in your cash flow build, your line item said “Less: change in NWC” and you added it, it’s slightly more forgivable because you obviously know to add it but didn’t check thoroughly (sometimes under time pressure the reverse sign of NWC can catch you off guard). If you added capex or something then it’s like, you should most certainly catch that).
 

Chances are nobody else fucked that up so you’d have to have done everything else very well, or added value elsewhere. If, for example, you had a more thought out base case, or tried to do some operational sensitivities that somehow stood out a bit, then I’d give you a pass if you didn’t completely blow the model up.