Looking at the implementation of IO::Interactive, it's essentially -t plus some code to handle *ARGV magicness. In other words, it shares the same problem of possibly producing incorrect results when being (mis)used to test if something is running in the background (e.g. when a script is sent into the background using &, executed from an (interactive) command line):

$ ./724312.pl  
Running interactively

$ stty -tostop  # just in case
$ ./724312.pl &
[1] 13831
$ Running interactively
[1]+  Done                    ./724312.pl
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