Some more explanations about PMS oddities :

Private Sequences are 'Implicit VR', (and their length is *not* 0xffffffff)
Readers cannot know it's a Sequence; they just read it as a long value.
If we take into account Phillips Intera 'shadow dictionnary', same problem as
for MR_Philips_Intera_Broken.dcm occurs again, *for 2 reasons* :

endianess is swapped inside  Private Sequence 2001|105f,
The TS was Implicit VR; it becomes EXPLICIT VR !

gdcm heuristics is broken :-(