Not necessarily. One of my aunts experienced the EXACT same situation. Had the perfect guy, but once married he completely changed and became abusive. It took maybe a month and they were separated.
Bestie is probably one of the strongest, most well rounded characters on the show. All she needs is a tiny bit of a shove in the right direction and Puck's little break down did that for her. I never did see it taking long for her to get out. Which really if you think about it, is what they are encouraging. People who are in that situation to get out. And if this side plot and what happened on tonight's episode was enough to encourage even one person in an abusive relationship to get out then, well it's a good thing.
I'm just glad they touched on the subject and continued with the side plot at all since it was introduced. Plus we know that one hour long episode covers one or two weeks worth of time and this side plot was introduced a couple of weeks ago. So reasonably 3-5 weeks could have passed in the characters' lives. Some people do get out that quickly once it starts and the whole point of even "going there" was to encourage people to get out sooner rather than later.