The GANews daily dose of accidents https://generalaviationnews.com/2017/05/15/planes-collide-on-runway/ is interesting. Both pilots were on airspeed, and both transmitted at least one position report. However a tight pattern by the higher and much faster aircraft, and difficult to see plane on final resulted in two masses attempting to occupy the same space at the same time. The NTSB docket includes a flight path map of both aircraft in the Video Factual Report https://dms.ntsb.gov/public/57500-57999/57864/581933.pdf. 'See and Avoid' didn't work so well, despite the recorded efforts of the pilot who landed atop the slower aircraft.

Was ADSB involved?

I might have missed it- But did not see any reference to mutual
radio contact or replies.

I survived 17,000 hours in slow airplanes, usually without radio, by staying low and close, checking very carefully for fast airplanes on final, giving way to all, spending very little time on a short final at an angle to the runway, and getting off at the first turnoff. It is really dangerous on final or on the runway. Limited exposure.

ADSB was not mentioned as available in either Final NTSB report, nor in the Docket.

The NTSB Docket contains the statement of a CFI who said he heard both aircraft transmit one position report. However, the CFI was using a handheld radio and was also disracted by his student. He said other radio calls may have occured that he did not hear.

The Pitts called in 7 miles out and at left downwind entry. The other aircraft involved in the accident, a V Star, called in reporting 1/2 milefinal.

There is no record in the docket or NTSB Final,reports of the two involved aircraft establishing direct communication. https://dms.ntsb.gov/public/57500-57999/57864/581936.pdf and https://dms.ntsb.gov/public/57500-57999/57864/581937.pdf https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20150514X71458&AKey=2&RType=Final&IType=LA https://app.ntsb.gov/pdfgenerator/ReportGeneratorFile.ashx?EventID=20150514X71458&AKey=1&RType=Final&IType=LA

Here's the NTSB Video Factual Report from the Docket: https://dms.ntsb.gov/public/57500-57999/57864/581933.pdf

This image is the mated biplanes: https://dms.ntsb.gov/public/57500-57999/57864/581938.pdf