Brave Big Black Beetle

I went for a walk at Amwell Nature Reserve this afternoon. I only saw one dragon and there were very few birds about. As I walked back from the White Hide I saw a big black beetle on the path. I lay down and took some shots and then picked it up and put it on a post where the light was better. I thought it might fly but it started to scramble down head first. I'd noticed how clingy its claws were when I picked it up but I couldn't let it continue and put it back where I found it.

I didn't realise until I looked at my pics that it is missing a foot. :( So pleased that I didn't leave it to struggle. I think it is a lesser stag beetle. I've read that they are characteristically lethargic and clumsy night flyers.