can anybody show me video evidence of Ward using headbutts or dirty tactics?

[BennyST]

when Ward misses with a punch, he follows in with his head to disguise it from the ref...

Yeah, he has the Hopkins trick down well. It is an intentional headbutt, but it is very well disguised with punching. It works well, it hurts like hell, and while it's not as obvious as just jumping straight in with your head ala Ortiz, it is still deliberate.