Looked at your link Factor - I did wonder to myself - he hung onto the competitors' chairs for dear life. Am wondering is he having difficulty breathing. I do wish him well.
I used to love Casualty. Haven't watched it for years now. I've just had a brief look, and agree he's not a great actor. He still looks almost as young as he did 20 years ago, just less hair.
I don't suppose Duffy is still there? I remember her accent changed from pure Bristol almost to RP over the course of a couple of series.
Charlie is a mainstay within the programme, if he couldn't act or if he put viewers off in their droves the programme makers would soon have him ousted.
I think he portrays the inward sense of loneliness and angst whilst appearing on the outside to all his colleagues as capable and happy.
I agree with the OP and have thought that for years...he cannot act. He always look vague, he NEVER looks anyone in the eye for longer than a few seconds, and has been the same in other stuff he has been in such as the gentle touch and the long good Friday.
I think we're getting too Americanised. We want our actors to act a certain way for escapism....and not the benefit of the drama/programme/film....whatever.