I don’t know why, but there seems to be no safeguards against launching multiple instances of My OSMC. I’ve managed to launch 17 instances on top of each other (counted the number of times I had to close it) because there was no feedback or reaction when launching it. It is not uncommon for IR remotes to be aimed improperly or otherwise not have their signal go throug (bad batteries, CEC problems etc.) so it’s not that far fetched to press buttons repeatedly.
Needless to say the addon becomes pretty unresponsive when running 5+ layers of itself, and it’s not apparent why since they all launch at the same time after perhaps 5-10 seconds.
On a side note, there are some other addons with the same behavior, as well as some that prevent multiple instances.