I sent a former colleague a LinkedIn request, but acknowledged that we had not met. He replied with an existential question that if the email constitutes a meeting, I can no longer say we never met. I replied that it should be a grammar problem rather than an existential one. I should have said “We have not met yet.” This way it is true at the beginning of the sentence, and by the end of the sentence we have. That would have been a smoother transition from present to past.