I was in a text exchange with a friend from Mexico. English is his second language. He deigned to correct something I, whose English is my first language, texted... "When you, me, Tony, and Gabi met here it was March 16, 2016, a Wednesday." He reasonably thought it should be, "When I, you, and Tony..."

I talk good so I desperately searched the Internet for an answer that would put him back in his place. I came across this page where StoneyB explained that the Cambridge Grammar of the English Language defines "when" as a preposition" which should be followed by an objective pronoun (such as me, him, her, and us) rather than a subjective pronoun (such as I, he, she, and we).

"Woohoo!", I'm thinking. That's how I destroy... err, I mean correct my friend. So, do you think, "When you, me, Tony, and Gabi met here..." is correct, or at least not wrong? Thanks!