Spun engine coupler and taking on water

[mp66226]

I spun the engine coupler on my 99 sea ray with 5.0 mercruiser alpha. I am getting ready to pull the engine to replace it. I dont know if it is just a coincidence or not but since a couple of hours before the coupler went out, the boat has been taking on a lot of water. I also noticed a "sympathetic" oscillating hum or moaning sound whe running during this same time. First time t thought my wife didn't tighten the plug enough. Initially I thought I spun the prop hub so put on a different prop and hub and put it in the water again, having tightened the plug myself to make sure it didn't leak. Well, went to run again and would only go with rpms at idle. If I throttled up the prop would quit spinning. I now know for sure it is the engine coupler. But, in the 15 or 20 minutes in the water it took on a lot of water. Pulled the outdrive last night and the yoke and u joints are fine, the bellows all look and feel good, don't know for sure what caused the blown coupler but the boat has about 1800 hours on it and I'm pretty sure the coupler has never been changed. Can blowing an engine coupler do some damage somewhere to cause a leak?