It very well may be correct. According to the IRS:
"Net investment income from annuities is reported to a recipient on Form 1099-R, Distributions From Pensions, Annuities, Retirement or Profit-Sharing Plans, IRAs, Insurance Contracts, etc. However, the amount reported on Form 1099-R may also include annuity payments from retirement plans that are exempt from NIIT. Amounts subject to NIIT should be identified with code “D” in box 7. If code “D” is shown in box 7 of Form 1099-R, include on Form 8960, line 3, the taxable amount reported in box 2a of Form 1099-R."
Your husband's 1099-R that reports his pension income may have a code "D" in Box 7 of the Form, which will result in an amount being included on line 3 of Form 8960. The 1099-R for your annuity may not have a code "D". in which case your annuity will not be included on line 3 of Form 8960.