Hilchos Lashon Hara, chapter 2, section 2

Chazal (our Sages) allowed speaking "in front of three." This is about something that is not clearly bad, but can be understood in two ways – good or bad. How it sounds depends on the speaker's tone.

If a person says something like this in front of three people, it is allowed. Since the speaker knows the words will surely reach the person they are talking about, they will say it in a positive way.