ExRootAnalysis loses particles when converting from STDHEP to ROOT

I am looking at a scenario in which a novel particle, let's call it a1, decays to two taus. These events are in an LHE file, which is passed to pythia to handle the tau decays. The hep file from pythia is then given to ExRootAnalysis for conversion to root for further analysis. However, in the root file, only one of the taus is present! Furthermore, it's parent is incorrectly listed as the parent of the a1, rather than the a1 itself.

Here is an LHE event:
<event>
 7 1 0.5560000E-01 0.7499995E+03 0.7818608E-02 0.9635351E-01
       21 -1 0 0 502 501 0.00000000000E+00 0.00000000000E+00 0.37500000000E+03 0.37500000000E+03 0.00000000000E+00 0. -1.
       21 -1 0 0 501 502 0.00000000000E+00 0.00000000000E+00 -0.37500000000E+03 0.37500000000E+03 0.00000000000E+00 0. -1.
  9000006 2 1 2 0 0 0.00000000000E+00 0.00000000000E+00 0.00000000000E+03 0.75000000000E+03 0.75000000000E+03 0. 0.
  9000005 1 3 3 0 0 0.00000000000E+03 -0.37496666519E+03 0.00000000000E+03 0.37500000000E+03 0.50000000000E+01 0. 0.
  9000005 2 3 3 0 0 0.00000000000E+03 0.37496666519E+03 0.00000000000E+03 0.37500000000E+03 0.50000000000E+01 0. 0.
      15 1 5 5 0 0 -0.462406 276.665 -1.21018 276.673 1.777 0. 1.
     -15 1 5 5 0 0 0.462406 98.3019 1.21018 98.3265 1.777 0. 1.
</event>

Here is an event from the pythia log:
    1 !p+! 21 2212 0 0 0 0.00000 0.00000 6499.99993 6500.00000 0.93827
    2 !p+! 21 2212 0 0 0 0.00000 0.00000 -6499.99993 6500.00000 0.93827
 ==================================================================================================================================
    3 !g! 21 21 1 0 0 0.09917 -2.23705 374.99463 375.00131 0.00000
    4 !g! 21 21 2 0 0 -0.38334 1.74791 -374.99463 374.99890 0.00000
    5 !g! 21 21 3 0 0 0.09917 -2.23705 374.99463 375.00131 0.00000
    6 !g! 21 21 4 0 0 -0.38334 1.74791 -374.99463 374.99890 0.00000
    7 !phi! 21 9000006 0 0 0 -0.28417 -0.48914 0.00000 750.00021 750.00000
    8 !a1! 21 9000005 7 0 0 -0.14277 -375.20602 -1.99230 375.24465 5.00000
    9 !a1! 21 9000005 7 0 0 -0.14140 374.71688 1.99230 374.75556 5.00000
   10 !tau-! 21 15 9 0 0 -0.56751 276.48714 0.26013 276.49281 1.77700
   11 !tau+! 21 -15 9 0 0 0.42611 98.22998 1.73217 98.26225 1.77700
 ==================================================================================================================================
   12 (phi) 11 9000006 7 13 14 -0.28417 -0.48914 0.00000 750.00021 750.00000
   13 a1 1 9000005 8 0 0 -0.14277 -375.20602 -1.99230 375.24465 5.00000
   14 (a1) 11 9000005 9 15 16 -0.14140 374.71688 1.99230 374.75556 5.00000
   15 (tau-) 11 15 10 21 23 -0.56751 276.48714 0.26013 276.49355 1.77700
   16 (tau+) 11 -15 11 24 25 0.42611 98.22998 1.73217 98.26224 1.77700
   17 (u) A 12 2 1 26 26 -0.22052 1.05682 2885.97102 2885.97122 0.00000
   18 (ud_0) V 11 2101 2 26 26 0.34230 -0.54873 -5383.13720 5383.13724 0.00000
   19 (ud_0) A 12 2101 1 50 50 0.12135 1.18024 3239.02816 3239.02837 0.00000
   20 (u) V 11 2 2 50 50 0.04104 -1.19918 -741.86198 741.86295 0.00000
 ==================================================================================================================================
   21 nu_ebar 1 -12 15 0 0 0.05961 141.21529 -0.09714 141.21533 0.00000
   22 e- 1 11 15 0 0 0.30867 42.98817 0.16480 42.98960 0.00051
   23 nu_tau 1 16 15 0 0 -0.93578 92.28368 0.19247 92.28862 0.00000
   24 nu_taubar 1 -16 16 0 0 1.11942 61.10420 1.05875 61.12362 0.00000
   25 pi+ 1 211 16 0 0 -0.69331 37.12577 0.67342 37.13862 0.13957
   26 (string) 11 92 17 27 49 0.12178 0.50809 -2497.16618 8269.10846 7883.03974
   27 pi+ 1 211 26 0 0 0.18100 1.04168 1414.16532 1414.16573 0.13957
   28 (rho-) 11 -213 26 73 74 -0.51199 -0.48929 717.15393 717.15481 0.87392
   29 (omega) 11 223 26 75 77 -0.00526 0.37236 84.80181 84.80619 0.77733
 etc....
All good so far. Looks like semileptonic tau decay.

Then, here is a listing of all the particles seen in the root file produced by ExRootAnalysis:
0 PID: 2212 Stat: 3 Mother: -1 Daughters: -1 - -1
1 PID: 2212 Stat: 3 Mother: -1 Daughters: -1 - -1
2 PID: 21 Stat: 3 Mother: 0 Daughters: -1 - -1
3 PID: 21 Stat: 3 Mother: 1 Daughters: -1 - -1
4 PID: 21 Stat: 3 Mother: 2 Daughters: -1 - -1
5 PID: 21 Stat: 3 Mother: 3 Daughters: -1 - -1
6 PID: 9000006 Stat: 3 Mother: 4 Daughters: -1 - -1
7 PID: 9000005 Stat: 3 Mother: 6 Daughters: -1 - -1
8 PID: 15 Stat: 3 Mother: 6 Daughters: -1 - -1
9 PID: 9000006 Stat: 2 Mother: 6 Daughters: 10 - 11
10 PID: 9000005 Stat: 1 Mother: 7 Daughters: -1 - -1
11 PID: 15 Stat: 2 Mother: 8 Daughters: 16 - 18
12 PID: 1 Stat: 2 Mother: 0 Daughters: 19 - 19
13 PID: 2101 Stat: 2 Mother: 1 Daughters: 19 - 19
14 PID: 2203 Stat: 2 Mother: 0 Daughters: 41 - 41
15 PID: 2 Stat: 2 Mother: 1 Daughters: 41 - 41
16 PID: 16 Stat: 1 Mother: 11 Daughters: -1 - -1
17 PID: -211 Stat: 1 Mother: 11 Daughters: -1 - -1
18 PID: 113 Stat: 2 Mother: 11 Daughters: 65 - 66
19 PID: 92 Stat: 2 Mother: 12 Daughters: 20 - 40

One tau is gone!

Any help with this would be very appreciated.

Best,
Matthew