Not that it was any excuse at all for what Brooke did, but Deacon and Bridget were doomed from the beginning. She was naive and stupid and Deacon was opportunistic and wanting to spite the Forresters for supporting Amber's marriage to Rick. If Brooke hadn't come between and no other cheap floozy turned his head, Bridget would've wised up eventually.
People love to drag Brooke for this, and say nothing about Taylor sneaking around with Rick, but the only difference in those examples is that Bridget's rage over the event didn't get her killed.
Bridget is no bullshit the closest thing to a saint the show has ever had, but she's also been allowed to have real emotions and reactions to the shit happening around her without going way over top. Like when Nick told her about boinking Katie in Catalina, there was no surprise in her voice, just a "WTF really dude" and "Ah shit, here we go again" and tossing her ring after learning Katie was knocked up on top of it. No muss, no fuss and she didn't give them a second thought until TPTB had to split Kick up to get Heather Tom and Don Diamont some screen time together. Such a shame their chemistry was never put to good use on Y&R, but I digress.
Overall, she's a good girl, but a strong one who moves on with her life and in the one instance where she was overly insecure and petty towards a woman (because of Nick keeping secrets, even one that any decent person would have kept and he was in a Kobayashi Maru situation somewhat), she realize she was wrong and apologized. She didn't even use the excuse of her grief to shriek her ONS with Owen or throw up Nick's history (save for one line) as a reason to save their marriage.
You know, I'd rather B&B never bring Bridget back, because history has proven they will fuck it all up again and shit over that history. TIIC had no issue taking a wrecking ball to Ridge's very few redeeming qualities these last few years, so why would Bridget's history be safe?