Yep, they were nice to Trea after booing the crap out of him for quite some time before that. Did we boo Jason Werth like that when he came over from Philly and hit .232 for us his first year?
I remember them coming to DC and booing loudly when Zimm got his silver slugger award prior to the first game of the season one year. They are always obnoxious whether it's a Phillies game in Nats Park or Eagles game in Fed Ex. Try wearing your Strasburg jersey and curly W hat to a Nats game in Philly. I've never seen a visiting fan mistreated at Nats Park. My son and I went to Philly for the Nats second game ever in 2005. We caught crap with our Nats stuff on, but it was some sweet action when Jose Vidro won the game in the 10th with a home run.
I could give more examples but I think you're just joking about them changing.