Mixed-signals
They had nothing to say to each other.
She'd gotten the signals wrong- she wasn't flirting with her, she was just being friendly without the realization of her over-friendliness.
They hadn't spoken about that night, about that incident. If Caldwell ever found out that she'd hit on Weir, blood would be spilt-her blood.
It really wasn't a wise idea to hit on Elizabeth, fully aware of the consequences.
But, she'd rather face the consequences of a dishonorable charge than talk to Weir about that night, because sadly, she wasn't Kate.
Had she been, then the situation would've been very different indeed.