Factual error: When Jack is speaking to his mom on a mobile phone outside of his apartment door, he tells her that he will take her to Souplantation after she comes over that afternoon for a blowout. Jack's apartment is in Manhattan. Souplantation is a restaurant chain that only exists in California. (00:19:35)
With Enemies Like These - S11-E3
Continuity mistake: Sharon Timmer introduces herself to Grace in Series 10 Episode 1: "I've lived directly below you for 19 years." But then in Series 11 Episode 3 she seems to live in Flat 9B next door to Will and Grace. I'm not sure we've ever seen who lives there before, but guessing by the layout of Will and Grace's flat, there wouldn't actually have been space for an extra flat in that space. (00:00:16 - 00:12:12)
