With Waller in Sydney for the Golden Eagle meeting, stable representative Darren Beadman praised the ride of Shinn.
"That was a 12 out of 10 ride," Beadman said.
"We were quite fortunate that they did roll along in the race, running good sectionals, which probably allowed him to be a little bit further back and just to rest her.
"She chimed into the race probably a little bit too well and got to the front probably a little bit too quick, but we won't knock that one back."
Beadman said De Armas was an improving filly, but her manners on race day need improving.
"She still did a few things wrong," Beadman said.
"She laid out, she didn't really get around Caulfield the other day, but the big track here obviously suits her.
"She's obviously entered for the Oaks on Thursday, so Chris and the team will see how she pulls up, but OTI have got a very handy filly on their hands."
For Shinn it was his third win in the Wakeful Stakes having guided Thunder Lady (2011) and Luvaluva (2017) to victory for John Sargent.