Bingo. You'll most likely never know, just take care of yourself and chalk it up to the bugs you've had in your life. I will say this, with frozen foods you need to follow the cooking instructions and make sure its as hot as its supposed to be. I've read more than once that half cook frozen foods can be a source of bacteria more than many other improperly prepared foods.
As someone who works with food (and even completed a "Follow Workplace Hygiene Procedures" course to do so), food is supposed to be heated to at least 75°C (167°F) before serving. The temperature in refrigerators must be below 5°C (41°F). It is recommended that high risk foods (dairy, meat, etc.) not be returned to the refrigerator if they have been out of it for more than two hours cumulatively*, and that they be thrown out if they've been out (and at a temperature lower than 60°C [140°F]) for more than four hours cumulatively.
*If you pull some cheese out for five minutes while you make a sandwich, put it back in for an hour, pull it out again for ten to grate some for pasta, that's fifteen minutes cumulatively.
Also (according to a friend who completed a science degree relating to itsy bitsy lifeforms), food that has had a sufficient quantity of various bacteria can still make you sick even if the bacteria themselves are dead, as it is the toxins they produce are what makes you sick, and those are not necessarily destroyed. On the plus side, getting rid of toxins takes a lot less time than fighting off bacteria.