The boyband previously claimed that they were forced to face a wall when Spears passed them, though her representative later denied the allegations.
Singer Jay McGuiness has now told Metro that the incident was likely the result of "some pushy security".
"Nine times out of ten, if people make it that far, it is because they are nice," he added.
"The people around them, it's their job to be a little d**kish - Christina [Aguilera] is probably the exception to that."
McGuiness continued: "If Britney was a cow, we'd just say it, but she wasn't. We are just honest."
The group also added that Spears is "lovely and friendly".
McGuiness's bandmate Tom Parker last month dubbed Aguilera a "total bitch" and though he later regretted the slur, he also added that "manners cost nothing"
When it was suggested that Lady GaGa could be the next target of the group's barbs, Parker said: "I'll happily stay away from GaGa."