Yes, Dom hid the bruises for ages and although the others suspected what was going on, and tried to stage an intervention, Dom refused to admit it. Then one day, he and Isaac had a row at work (at the top of some stairs, obvs). Isaac made a threatening move towards Dom, who stepped back and fell down the stairs. He was quite badly injured and in treating those injuries, HH discovered older bruises and fractures that had gone untreated, and was able to persuade Dom to report Isaac. It was a really moving episode and built up a lovely relationship between Dom and HH and Sacha.