By “got away with it” you mean most weren’t hanged. All but one of the few who made it to Pitcairn Island were dead after some 10 or 15 years. Bligh managed to sail close to 4000 miles in an open boat with the crew loyalists. The Royal Navy spent some time searching out the mutineers but never found the ones on Pitcairn Island.
William Bligh was anything but a brutal captain. He was a brilliant navigator — learned his trade under Captain Cook himself.
When you look at the historical record objectively, Bligh was no villain, indeed, quite the contrary. Compared with other captains of his era, he didn’t often resort to harsh punishment. He generally looked after the welfare of his crews.
He managed to sail hundreds of miles in an open boat to reach safety in the Dutch East Indies and lost only one of his loyal crew members. This would be an amazing feat of seamanship in any era.
The worst that can be said about Bligh is that he had, at times, a short fuse and a sharp tongue. He didn’t suffer fools gladly, and that got him into trouble on occasion.
Bligh was a hero, in the real Bounty drama. Fletcher Christian was a misguided fool who went soft over the prospect of an easy life in Polynesia. It didn’t turn out well for him or most of the other mutineers.