Offset sometimes incorrect number of ticks away

[sa7med]

Hi, i've noticed this happening every now and then:

3/28/2018 07:54:47: [Excel] : £ 15.00 Back bet placed on Tossapenny at 1.73. Fully matched at 1.73. Ref: 120506727046 ( Fill or kill bet with 120 seconds delay. Offsetting by 2 ticks with greening. )
3/28/2018 07:54:47: [Excel] : £ 15.26 Lay bet placed on Tossapenny at 1.7. Entirely unmatched when it initially reached the market. Ref: 120506727106
3/28/2018 07:54:53: [Excel] : Modify bet persistence 120506727106 from 'Cancel' to 'Keep'

As you can see the offset is 3 ticks away rather than two. My guess is it occurs when there is a sudden 2 tick price shift but can't be sure. Thought i'd mention it.

[Euler]

It's probably a timing thing. At the split second the offset goes in the price is different, or perhaps a partial match at a different price.