usage of QString::arg with place marker "%0"

Here: http://qt.gitorious.org/qt/qt/blobs/4.7/src/3rdparty/phonon/gstreamer/mediaobject.cpp#line224
Code:
setError(QString(tr("Plugin codec installation failed for codec: %0"))
.arg(m_missingCodecs[0].split("|")[3]), error);

The method "arg" is used for a string with wrong place marker "%0". Qt documentation (http://doc.qt.nokia.com/4.6/qstring.html#arg) says: "Place marker numbers must be in the range 1 to 99.", so "%0" should be replaced with "%1".

P.S.: I am not sure if this mistake leads to something bad or it just works.