Mxsmanic wrote in
:

A departure from controlled flight, such as a stall or spin, or in
some cases simply slips or other uncoordinated movements that may make
passengers queasy.

Slips and uncoordinated flight are not caused by turning the plane with only
the rudder, unless perhaps done very sharply. Aileron input is required in
order to maintain a slip or uncoordinate flight. Without aileron input the
plane will bank by itself during the turn. There are aerodynamic reasons for
this phenonmenon that I will let you look up online somewhere.

Apparently so, in some cases, based on what I've read. The stuff I'm
reading claims that it's a common mistake in phases such as landings,
and sometimes it kills the pilot.

No. This is inaccurate. Stalls and spins are not caused by the turning of the
plane with the only the rudder. Incorrect coordination of rudder and ailerons
can turn a stall into a spin, but that doesn't cause the stall.