Background
I am running Lost Mines of Phandelver and yesterday my party got to Phandalin. One of the party has a background about wanting to help civilise the place (Which he reads as wanting to run it and thinking he has the right to take charge) and tried to confront the Townmaster after hearing how inept he is (From one person!). Due to the time they arrived I said the Townmaster was at home rather than in the office, so the party actually smashed his door down to confront him in the middle of the night.
In an attempt to show the party these are real people I made up a young frightened daughter on the spot, which vaguely did the trick but they still actually confronted the Townmaster (Albeit with weapons sheathed) as he was comforting his terrified daughter before leaving.
Dilemma
I don't want to have them arrested or anything, as I have made it clear the law in the town has no real enforcement, however I do want some consequences.
I figure the Townmaster is too cowardly to really do anything, else he would probably have dealt with
the Redbrands.
already. My suggestion, since the characters used their real names, is to have Sildar find out about what happened (The characters were split up at the time so only half of them went to pick up the Townmasters quests which gives me a nice window for him and Sildar to have a conversation off camera) and confront the party; as Sildar is a nice person and grateful for his rescue it likely wouldn't lead to arrest, and if it did I would expect an escape attempt where things would spiral out of control.
I know having things spiral out of control isn't necessarily a bad thing, and I could probably handle it, but as a first time DM I would like to keep them a bit more on track, while shadowing how I hope they will act when we end LMoP and start a proper campaign.
Question
How do I show my players that there are consequences (In this limited set of circumstances where there are actually few consequences), without just having Sildar lecture them about their responsibilities and how they need to be seen as better than the Redbrands?