Why does FFMPEG different arguments' placement create different mov clips?

I use ffmpeg to cut the first 4 seconds of a mov 14 seconds video file.

This is the command I use (on Ubuntu) to create the new clip:

ffmpeg -i H264_test1_Talkinghead_mov_480x360.mov -ss 0 -t 4 -c copy test_1_seg.mov

Alas, with this command, even though I can hear the audio from the start of the new clip, the video starts showing only from ~1 second.

However, if I change the arguments' order in the command slightly, I can see the video from the start:

ffmpeg -ss 0 -t 4 -i H264_test1_Talkinghead_mov_480x360.mov -c copy  test_1_1_seg.mov

1. Any idea why the order of arguments matters?
2. Is that a bug/feature?
3. Can other arguments' placement have impact on ffmpeg output?

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The original (14 seconds) file is test.mov
The faulty new clip (first 4 seconds) file is test_1_seg.mov
The correct new clip (first 4 seconds) file is test_1_1_seg.mov

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