Yes it's cheating
To stir the pot a little, how is that different than putting a 15 7/8" fish in the live well and have him relax and grow on you? Your still going to get a ticket and you would still be violating the rules.

What if the fish tail touches the 16" mark but does not go over it. Legal or not legal?

If it touches 16 inches it is considered 16 inches which is not legal

Bass 16" or less and 24" or greater may be retained.

If it is over 16" it is illegal by the letter of the law. Slot includes fish over 16" and under 24".
Some tourneys will not weigh a fish that touches 16", though it is a legal "keeper" by law.

But if you are hauling one around that is illegal, yes that is cheating as well as breaking a state law.

If it's right at 16" that's a legal fish, same with exactly at 24" and yes fish do shrink, they'll tense up and get shorter from tensing up, also very cold water will make them shrink, don't do these things but I've seen people do it, now never seen anyone cut a tail or anything like that, and reason they suspect a mad dog fishermen cause the tail wasn't bloody usually if you trim a tail the tail normally gets bloody, I've heard people burning a fishes tail to keep it from getting bloody. Which is all wrong

This is true. My dad weighed in a fish that was touching the 16 inch line at Big Bass Splash the other day.

I can't believe someone even asked this...

How could they know it was someone from the Mad Dog Tournament.
What a crock of a statement to make.
Fishermen entered into a tournament designed as a "benefit" for a fallen public servant, knowing a large chunk of the entry fee will be donated, and you are going to accuse them of cheating,,,,,,give me a break.

True! Ask Robby Rose. He beat the polygraphs many times.

Yes, it's cheating. However, it's always been kind of backwards to me that GW gave tickets on Fork for fish that measured close but barely illegal. If fish grow & shrink in the livewell, there's no telling whether that fish was legal when the angler made the decision to keep him or not. I'm not a tournament fisherman and don't really care, but I've seen it happen and it always rubbed me the wrong way.

As for the polygraph, yes it's a joke.

And as for the "what if it barely touches the 16" line", that should be an illegal fish. There's no such thing as a 16.00000000000...000" fish. If it touches the line, it's over 16" (even if it's a tiny, tiny amount), and it's a slot. Conversely, if a fish touches the 24" line, it's an over. JMHO, and it's worth what you paid for it.

what part of 16 to 24 is that hard to understand.
16 to 24 is a slot fish , so a 16 is a slot, and a 24 is a slot

must be however slightly under 16
and must be however slightly over 24.

There is a lot of shady activites in these big bass events, some knowingly, some by stupid people that just don't get it... Example: I was in line at the Legends and the dude in front of me was kneeing, and banging on the blk bag his fish was in, I asked him whats the deal with all that. He answered me with, I want to spook the fish so it's scared, and tenses up.. I shook my head and just laughed...

Wrong wrong wrong. Geez, it's not that hard.

Black bass
For largemouth bass, length limit is a 16-24� slot. Bass 16 inches and less or 24 inches or greater in length may be retained. Only one bass 24 inches or greater may be retained each day. For smallmouth bass (if present), minimum length = 14 inches. No minimum length on spotted and Guadalupe bass (if present.) Daily bag limit for all four species = 5 bass in combination.

http://tpwd.texas.gov/fishboat/fish/action/fishregs2.php?water=0433

Neither a 16" nor a 24 inch bass is in the slot on lake Fork.