This is probably a long shot but...
I was a passenger on SY105 on July 5th, KMSP to KLAS -- during the flight, at approximately 5:21PM CT (plus/minus 2 minutes), while at or near cruise altitude there was another jet aircraft visible out of the left side of the cabin window. I was unable to identify the other aircraft as it was traveling in the opposite direction and moving fast, so this happened quite quickly.
I would estimate that the other aircraft was approximately 1/4 mile away, and certainly less than 1 mile away. The other aircraft appeared to be flying at an altitude approximately 500 to 1,000 feet less than the altitude of us / SY105.
I'm not sure if this violates rules of separation or not, which is one of the reasons I'm posting (I'm just an aviation nerd & student pilot who should have had his PPL several years ago). I'm also curious if anyone can find the ATC recordings that may have contained related dialog.
FWIW, I have searched a decent bit but I suspect we may have been under control of a center which is not yet covered by a feed -- I wasn't able to find anything so far though, but if anyone finds it I'd certainly appreciate it.
Summary:On July 5th at approximately 5:21PM CT, while traveling KMSP to KLAS on Sun Country Flight 105, an aircraft going in the opposite direction to us appeared awfully close. Any insight or related audio would be appreciated!