Does `patch` work with asymmetric context

I have file a:

This
file
does
have
an error
in it
that
needs
to be
fixed.

and a similar file b:

This
file
does
have
no error
in it
that
needs
to be
fixed.

I can create a unified diff with diff -u a b:

--- a   2018-01-03 14:20:22 +0100
+++ b   2018-01-03 14:20:37 +0100
@@ -2,7 +2,7 @@
 file
 does
 have
-an error
+no error
 in it
 that
 needs

And I can also reduce the context to one line on either side with diff -u1 a b:

--- a   2018-01-03 14:20:22 +0100
+++ b   2018-01-03 14:20:37 +0100
@@ -4,3 +4,3 @@
 have
-an error
+no error
 in it

Both of these patches can be applied cleanly with patch. I did not however find a way to make diff produce a patch with asymmetric context. I am assuming it cannot do that. So I tried removing some context manually, to make a patch with two lines of context before the change and one after:

--- a   2018-01-03 14:20:22 +0100
+++ b   2018-01-03 14:20:37 +0100
@@ -3,4 +3,4 @@
 does
 have
-an error
+no error
 in it

This seems valid to me in the unified format. However, patch complains that it had to resort to fuzzing:

patching file a
Hunk #1 succeeded at 3 with fuzz 1.

Am I doing something wrong or is (GNU) patch actually broken for asymmetric contexts because no-one imagined they would ever be used, since diff cannot make them anyway?

Also interesting is that the patch works if I reverse the asymmetry, that is one line before and two after:

--- a   2018-01-03 14:20:22 +0100
+++ b   2018-01-03 14:20:37 +0100
@@ -4,4 +4,4 @@
 have
-an error
+no error
 in it
 that