PVS-Studio warning V557 for MTASA

class CWaterPolySAInterface
{
public:
    WORD m_wVertexIDs[3];
};

CWaterPoly* CWaterManagerSA::CreateQuad (....)
{
  ....
  pInterface->m_wVertexIDs [ 0 ] = pV1->GetID ();
  pInterface->m_wVertexIDs [ 1 ] = pV2->GetID ();
  pInterface->m_wVertexIDs [ 2 ] = pV3->GetID ();
  pInterface->m_wVertexIDs [ 3 ] = pV4->GetID ();
  ....
}

This suspicious code was found in MTASA project by PVS-Studio static code analyzer.
Warning message is:
V557 Array overrun is possible. The '3' index is pointing beyond array bound. cwatermanagersa.cpp 595

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/