I am not entirely sure I get your point. You mean that if you mistype the comma in
(which would be just two elements of @array
similar to Perl5) and accidentally change it to a semicolon
then you get a multi-dimensional array? Do arrays automatically promote to multiple dimensions? If this is the case, then it is indeed a call for stupid mistakes, which are hard to uncover...
By the way: for me at least Perl 6 native multi-dimensional arrays do not seem to be essential. I mean they are pretty nice, but I could definitely live without them in Perl 6.0.0. At least, poor autrijus might have some less sleepless nights implementing hard-to-implement-only-marginally-useful language features...:-)