Also it is worth mentioning that Google Talk !== Google Hangouts Everyone who uses XMPP/iMessage/Adium to connect to Google Talk is: 1) Apparently missing some messages from Hangouts users. Haven't been able to track it down but it's gotten me in trouble with my girlfriend a few times for "ignoring her" 2) Your friends see you as "Online" on hangouts and send you messages, which often seem to relate to #1 (you never…
Shit, Hangouts itself is an unreliable message delivery system. [0]
At least once an month in both group chats and one-on-one chats I will get messages that seem out of context. Somewhere between many minutes and an hour later, the messages between the OOC one and the previous [1] message will silently appear. The "new" messages are inserted between the previous and OOC message, and bear timestamps that make it look as if they were never missing.
I've even had this happen while I had the conversation in question open in the damn client! It's super-fun to see ten or so "new" messages slide in between two already-delivered ones. :/
So, if you've ever wondering if you had a brain fart and overlooked an important message in Hangouts, you may very well have not!
[0] Yep, I'm using the latest software.
[1] Previous at the time I received the out of context message.