Couldn't they have used virtualenv with Python? Also, Python packages have a way of declaring dependencies including specifying the Python version that your package requires. This should've guarded against any incompatibilities. I don't think any of this was specific to Lua.
I don't think virtualenv would solve their problems here; they are installing their agent on a customer's machine. I imagine they didn't want to ship the entire Python interpreter or alternatively install whatever version they want to use on the customer's machine.
But you're right, I don't think Lua is unique in being able to fix this issue. I think it's more that the author was already very good with it and liked it.
