Xandra’s friend Lisa (solicitous, following me around, voicing gentle but increasingly urgent concerns that “the family” be notified) had retreated to a corner at some point to dial the number I gave her—and got off the phone with such a look that it had elicited, from Xandra, the only laugh of the evening.
again lazy writing. I swear there's no room for this event to have occurred. narrator was pretty thorough when initially telling the account, hence the "at some point."