At the risk of going off topic, you're quite right to point out...

At the risk of going off topic, you're quite right to point out the Shine's pending adoption of AASB 15 however:
* they are not required to adopt this for quite some time (1 Jan 2018)
* by the time it happens the current concerns with listed legal firms may have blown over
* a mature communication strategy could mitigate the risk to SP.
* impact is dependent on how conservative Shine is being on booking WIP.

Given this last point is based on a subjective assessment of the case book, the impact to SGH's WIP revenue may not be directly comparable to a future impact to SHJ's. There will certainly be an impact though.

As you have correctly pointed out, this is a change to 'on paper' earnings and does not impact cash flow. The market may not be mature enough to see this, but there are currently other 'irrational' factors depressing the SHJ share price (as a result of SGH) which may be gone by the time 2018 rolls around.