Pretty interesting article. I think it's very likely that malicious customers took advantage of them although they havent exactly responded with transparency
It was hilarious to see the people mocking doge when it first came out and was getting randomly tipped everywhere. It's even funnier now to see people so upset by it when it actually has value.
There was a fork in January too, so a number of people know that although serious it is hardly life threatening. I don't think Dogecoin is any more vulnerable to this than any coin that uses a blockchain.
I never saw Litecoin or any other coin fork itself