Cooked ground beef (tacos) tonight, feeling a bit unsure about eating it tomorrow. Cooking

I cooked store-bought ground beef for tacos I plan to have tomorrow. I do this about once or twice a month, and have done so without any problems so far. However, this time around, something seemed a bit off about the ground beef that's making me a bit unsure:

a) When I placed the beef "slab" on the pan, it almost immediately disintegrated. Usually, the beef slab takes a while to thaw out, and feels "harder" than this one did. (I took it out immediately from the refrigerator, where it was.)

b) It took a bit of a longer time to cook.

c) When finishing, I noticed a few pieces still had light pink inside. I tossed them. The others looked grey/white. This was at the point where cooking, the beef was becoming hard and not soft anymore, when I stopped.

I put the beef in a container. I'm feeling a bit nervous, though, for some reason, so could use expert opinions – do you think it's safe to eat? (I didn't use a food thermometer.) Many thanks!

Submitted November 05, 2016 at 11:55AM by thoughtfuldude13 http://ift.tt/2f3LkPG Cooking