No need to wait for the Form 5498 or provide any explanation with your tax return. This is simply a rollover of $10k of your distribution.
Enter the Form 1099-R exactly as received and in the follow-up indicate that you moved some or all of the money to another retirement account or back to the same account, then indicate the amount rolled over. TurboTax will include the entire gross distribution on Form 1040 line 15a or Form 1040A line 11a but exclude the amount rolled over from the amount on line 15b or 11b. TurboTax will also put the word ROLLOVER next to the line.