I have 2 CB shrimp almost 4+ years now never had a issue ,
I think it's how they are fed and the tank size
I also have a 6" lobster you would think he would make a meal out of my fish but he don't ,why because he can hide
he is just laid back in his rock not bothering a soul , I just used him for a example
most don't understand a lot of the times CB shrimp are housed in small tanks that right there will cause aggression
recommended tank size is 30g or larger
IMO 30g is still a tight fit for a CB shrimp as they can grow up to aprox 6"
I in all due respect don't think they should be housed in anything smaller than 60g
I keep them well fed and in larger tanks and there model citizens
in a 30g tank they have no true way of running to hide so they go into defense mode
heck if I had no were to run I would go into defense mode too it's called instinct
if you feel threatend are you going to just sit there or fight ?
CB shrimp come from the ocean that is huge plenty of places to run and hide to avoid confrontation , another example we take the CB shrimp from it's well known environment , and place it in a small 24'x18'x11 glass box , than we wonder why they get aggressive it's not the shrimps fault in all reality it's ours .