It happens. The ground is so full of stuff now that sometimes you have to break other utilities out of the way to get to yours..i.e break out ducts,cables ducts and land drains etc.
Other utilities make the same mistakes. For example, a few years back some contractors moling in a field for UU doing water,moled through a gas main and a water main and filled the whole gas network of Corby with water..cutting off gas to thousands of customers for weeks..and needing the attendance of 100's of engineers,the abstraction of thousands of gallons of polluted water ,the replacement of meters,equipment and repairs/replacement of household appliances. Quite weird to see water jetting out of your cooker when you turn it on..