Right after I got the radiator fluid changed my water pump started leaking. The shop that did it just said "sometimes that happens". Is there something they did wrong perhaps?

 

Not likely. How many miles? Water pumps are easy to change and not horribly expensive. Just be ultra-careful with the coolant. Make sure you capture it all, and don't let any escape.

 

I use to manger a quick lube place. Every now and then when we would do a radiator fluid change customers would come back with there water pumps leaking. Some time they get all gunked up from the old fluid and doing a flush just breaks it all loose. Maybe ask the shop to split the cost with u? Wouldn't hurt.