It would of helped if you stated what the firmware update procedure was in the first place. What is used and where did you get the file from.
I don't know about Mac, but I (and most TV manufactures) would like to assume, using a USB flash drive, it would be formatted to FAT32. Then would further assume it would be through a Windoz PC. You are lucky you didn't "brick" the TV (though I never heard of that happening before).
Abundant OTA television is what makes this country different from all others. Lets keep it this way.
The Internet is no place for streaming video.