All the above posters are correct, esp. Fogcity. I would challenge you with a counter-example to your argument.
If tenses agree all the time, then every time we talked about something we saw, we would be confined to the past tense...
"OMG. Sally just wrote on Facebook that she and Mark were dating."
"I saw on the news that President Obama visited Birmingham next week."
"The fortune teller predicted that I scored really well on next month's SAT, but I'm still nervous."
Granted, these are blatantly obvious examples of poor grammar, but I encourage my students to think critically on their feet, and come up with reasons for themselves why something may or may not be wrong.