I have noticed this in a recent match as well, where my healing stats were especially obscene and dramatically different from the displayed total.
The actual total should've theoretically been 169,058 I believe, counting self damage.
Edit: As mentioned in the next post, the reason Victor has less total Healing done than actual Healing done, is because it is subtracted by all Self Damage he did that match.
The below screenshot demonstrates this.
99,909 - 69,159 = 30,750
Additionally, Barrier damage absorbed adds towards 'Healing done'.
Seemed a little unintuitive to me at first, but is fair and makes sense.
That makes a lot of sense in retrospect. I realized that after thinking about it again, and was going to come back to say this. This also answers the discrepancy mentioned in the original post.