In this web chat hosted by Channel 4 (UK)'s website, Terry O'Quinn mentions Dom specifically twice:

[...]

Oh~my~gosh! : Hi Terry, you rule! What’s it like working with the other cast members and whom do you get on with most??

Terry O’Quinn : It's a pleasure working with them. They are all younger than I am and no one gives me a hard time about that, which is good. I really love working with everybody. I just got done doing a scene with Dom and I love working with him, I like his process and he's a sweetheart. 

[...]

KateBarry : Have you learnt any British slang from Dominic Monaghan?

Terry O’Quinn : None that I can repeat, Kate! Naveen is actually more willing to put it out there.

[...]

http://www.terryoquinn.net/press/press_20051211_C4.html