I believe last night and the SB comeback were the only two times in TB's career of overcoming 13+ points in the 4th quarter.
In the SB, the comeback (with a deficit of 25 points) began in the 3rd quarter, whereas here (13 point deficit) it started with about 4 minutes remaining in the 4th quarter.
You can argue which was more unlikely. Probably the Super Bowl, as the Pats had only cut it to 16 with just under 10 to go, and needed to successfully convert the 2-pt attempt twice to force overtime. Although here it was literally down to the last seconds, including needing to mentally regroup after having the winning TD called off with under 20 seconds remaining (and backing them up from the 5 to the 15).