If they did not read him his Miranda rights, that could be enough by itself to basically throw everything out.
Matey, stop commenting on things you've only seen on tv. Reading someone their rights is only done under specific circumstances, and only applies to certain evidence associated with those circumstances.
Anyone who cares to learn can read about it here in the excellent illustrated guide to the law.
That's quite the axe you've got there, mr. ayyy. You been grinding it on any dragons lately? Just, bringing it up on random comments about internet behavior?