PVS-Studio warning V599 for Source SDK

class CFlashlightEffect
{
  ....
  ~CFlashlightEffect();
  ....
};

class CHeadlightEffect : public CFlashlightEffect { .... };

CFlashlightEffect *m_pFlashlight;

C_BasePlayer::~C_BasePlayer()
{
  ....
  delete m_pFlashlight;
}

This suspicious code was found in Source SDK project by PVS-Studio static code analyzer.
Warning message is:
V599 The destructor was not declared as a virtual one, although the 'CFlashlightEffect' class contains virtual functions. Client (HL2) c_baseplayer.cpp 454

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/