Cutting up video problems / overlap

ffprobe -i rw.mp4 -show_entries format=duration -v quiet
# Outputs:
#[FORMAT]
#duration=186.198000
#[/FORMAT]

# From this, I gather that rw.mp4 has a duration of 186.198 seconds.
# So why then, do these two videos not line up? There is overlapping footage in both videos.
/usr/local/bin/ffmpeg -ss 0 -t 181.198000 -i rw.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts -t 181.198000 -y rw_body.ts
/usr/local/bin/ffmpeg -ss 181.198000 -t 5 -i rw.mp4 -c copy -bsf:v h264_mp4toannexb -f mpegts -t 5 -y rw_tail.ts