At first, he was like "I don't know about this." Oh, shoot--you see what I did there? I actually think this is a useful distinction in English. When you say "X person said Y," then you are basically relaying a quote. Even if it isn't a quote, that objectivity is what you're going for. It's straightforward. It's the reliable narrator. If you say "X was like 'Y'," then there's some implied wiggle room. The "like" suggests that what comes next will probably be an approximation of a quote that is [slightly/majorly] changed to fit the mood of the story or the storyteller's agenda. It's less reliable, and a lot more conversational.
So there you go! Don't feel bad about "like"! Embrace it! It's the unreliable narrator of our lives! And don't worry about the blah blah ruination of the English language blah. Daniel agreed with me. He'd never thought about it that way. Then he told me I was a genius!* (*After I asked him to tell me that I am a genius.)
I've got a graduate degree, so I am an authority.
