I know the similar incident happend. Guess what? The guy who put knife inside the sandwich is Nepali guy. If its the same case I know the Guy. I always used to joke with him "K ho dai sandwich sangai chakku pani dine ta"  but I never thaught it would be so big issue.........agian if its the same case. 

I hope nothing happens to him, hes a very good man, he just had a bad day.