They ran in seven tries to finish second in Pool Three and book their British & Irish Cup quarter-final spot.
"There was some sloppiness in there that we'll have to rectify in the week," Cattle told BBC Radio Cornwall.
"I thought the score flattered us a little bit - it was only in that second 20 minutes in the first half where they missed a few one-on-ones."
Alex O'Meara scored a hat-trick at the Mennaye, with captain Chris Morgan, Bar Bartlett, Jake Parker, and Alex Day also going over.
Pirates had Marlen Walker sin-binned while fly-half Bartlett suffered a rib injury, with the club awaiting results from an x-ray.
"Us coaches are always going to be picky with the performance," added Cattle.
"When we had the sin-binning it looked a little bit disjointed from the scrum but they're things we can iron out."

President Evo Morales has announced a contingency plan, which includes $700,000 in extra funds for fumigation.
The swarm first appeared over a week ago near the low-lying eastern city of Santa Cruz, where most of Bolivia's food and meat is produced.
It has spread quickly, destroying pasture and fields of corn and sorghum.
The authorities estimate more than 1,000 hectares of agricultural land have been devastated by the locusts.
The government says fumigation must begin straight away.
"We will create a 500-metre-wide ring around the area affected and fumigate inside, working alongside the local authorities," said Bolivia's Agriculture Secretary, Mauricio Ordonez.
Mr Morales is due to visit Santa Cruz province on Friday.
Cornish Pirates coach Gavin Cattle says his side has room for improvement despite their 50-24 win over Connacht.
[NEXT_CONCEPT]
The Bolivian government has declared a state of emergency in a vast agricultural area affected by a plague of locusts.