[Cin]Weird "end of file" bug ?

I was playing with tvbars.ogg It goes from 2077 to 2099 But if you load it with Theora decoder there will be extra black frame near the end! i deleted it while locking audio. If you go with default ffmpeg decoder - last frame will be black! If i render corrected theora-decoded file as v410/s32 QT - I got weird diff between audio and video! If I disable write_tcmd in qt format (muxer) option A and V finally same length and video plays to 2099 framecount (on screen) But audio still few frames short! Anyone can replicate such strangeness?