Newbie with an offering and a question

One of the first matches I've ever played as an MG was here on PHL and this roadside ditch to be specific. I fought my way through what seemed like an endless horde until I reached a Gary. I went up to it, dismantled it by holding X (xbox) and the screen at the end said I didn't destroy anything.

Am I doing something wrong? I know I get them counted if I use explosives.

I'll try to post the end results in the comments.