The most common and most likely answer to this crossword clue is the 4 plus 6 letter word RISK FACTOR
I've seen this crossword clue in Financial Times
R
I
S
K
F
A
C
T
O
R
More clues leading to the result RISK FACTOR
Buddy explains!

The straight part
We know that "Margin for error" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case margin for error = risk factor.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.