From one planefag to another let me know when you can tie these in with an actual emergency, until then maybe you should slow down on the posts about these because they happen all the time.
The info can be reliable sometimes I have caught planes with engine failures, and inflight emergencies… but just look how rare hijacking are and theres your answer. Plus there is so much other information that can be gained by seeing where they go, what types are flying, etc.. There are other sites like flightradar24 and airnav radarbox that have more reliable squawk information for a small fee if you really need accurate squawk information. This was a hard lesson for me to learn too I always wanted to think that I was watching something unfold but because of the delay just know you would probably hear about a really bad emergency on the news first before catching it on these sites.
I've noticed this site will often show an emergency code when a plane is coming in for landing or takeoff too, not sure if emergency codes just get picked by the site as pilots cycle through codes or what but it definitely is not good at updating.