I think its about the windows cmd shell and its quoting needs.

These give me a good clue but i cant quite explain what i mean

perl -E "$,='|'; say  $^X, '-E', 'say for @ARGV', 1, qq(\\\x22), 2"
C:\Perl\bin\perl.exe|-E|say for @ARGV|1|\"|2
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perl -E "$,='|'; say  $^X, '-E', 'say for @ARGV', 1, qq(\x22), 2"
C:\Perl\bin\perl.exe|-E|say for @ARGV|1|"|2
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perl -E "say for @ARGV" 1 \" 2
1
"
2
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perl -E "say for @ARGV" 1 " 2
1
 2
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In the last case I SUSPECT windows is seeing " 2 as a single arg with an unterminated quote and its terminating it for us