Police: Are they winding us up?

Me and my bf went dumpster diving and I went and looked out and the police were coming down in their car so I bolted and so did he. Any how they didn't get out and chase us or anything and we went on a walk in the forest and the police came round and stopped for a second right next to us and flashed a white light on top of their car and then drove on. I know that dumpster diving here in the UK is a grey area but can be cled as thieving... do the police just find it funny that we ran just because we were bin ratching?