This same question was asked in a previous thread a day or so ago I believe ThirdEye says he does it I am of a different persuasion.
When meat is hot it is under pressure from the moisture in the mussel fibers expanding .Jamming a needle into said piece of meat lets the moisture out thus drying out the meat. Because the fibers are swollen up and tight anything you squirt in will run right back out cooling the meat down and prolonging cook time.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC