That's where he's getting the records.CORTANA: He's in my data arrays, a local tap.
She must have told Foehammer about the situation, why would Foehammer be near a Covenant held position with little-to-no backup without knowing what was going on? And why is Sargeant Johnson there either? heh, that's just a special ending but still...
Now, Cortana's initial escape plan is stupid, the lifeboats don't have engines so how can they escape the ring's atmosphere? The second plan (E419) was understandable, but I still don't know if a pelican can escape the ring before it asploded. The third plan (Longsword) worked.
If you read the books Cortana's primary concern is the survival of her and the Chief. Everything else is secondary.
And at the end of Fall of Reach, she double checks Cole Protocol and determines the coordinates to be random enough. She doesn't say it wasn't a blind jump nor does she say it was, thus she wasn't lying.