Shrewsbury goalkeeper Chris Weale fouled JP McGovern in the area on 68 minutes and Miller put United back on terms.
The game ended 2-2 but there was worse news for Carlisle with winger Matty Robson limping out of the game after only nine minutes with a suspected back problem
More top news
ITV Border's political editor Peter MacMahon shares his thoughts on the Chancellor's spending review
A look ahead at the forecast for the Border region.
Safety experts are to carry out checks on all 37 holiday chalets where a 59-year-old man died of suspected carbon monoxide poisoning.