In what ways was she "acting odd" and for days apparently, to justify you snooping on her phone?
The night itself seems very uneventful? Your wife went out with colleagues, you contacted her in the early hours, she responded, you offered a lift - after some consideration she accepted, you arrived and home you went. Is it that unusual for her to be sleepy and quiet at 3am? She must have felt tired&done as she called the night earlier than her friends.
And then we come straight to snooping, photos and her attempts to justify. 0 to 100 in 3 seconds.
My take: she went out with male and female friends from the office and didn't bump into guys later on. Why is she making out that it wasn't so? Me personally - I've only done that within relationships where jealousy and control have been an issue. To avoid that barely perceptible but menacing shift in demeanor that makes controlling relationships so very unpleasant.
In happy and secure relationships I share quite enthusiastically who I met, what we did, what was said.
Also, I would NEVER react well if interrogated about the results of snooping on my phone, particularly if being badgered for nothing. The more innocent, the more defensive, angry and questioning I would be about the intrusion.
If I was actually confronted with evidence of some nefarious deeds of mine, I would admit it there and then and the relationship would be over - as it should be. If it was just an attempt to control or an overreaction based on nothing, then the relationship would be over as well.
But she's still with you, so what do I know 🤷