'07 Tucson clunk

Here is what happened, stupid me...

I was sitting in a parking stall with the vehicle in neutral slightly pressing on the gas and rolling backward very slowly. I didn't realize I was in neutral as the shifter looked like it was in reverse. So basically I bumped the shifter which put the vehicle in reverse for real this time and CLUNK. The gear engaged and I was able to reverse and then go into drive and get home but that loud clunk I heard had me concerned. Anything I should be watching for after such an incident?

Thanks