To me something like "standard speed" is very ambiguous and open to interpretation. Especially above 10,000 where standard can mean as low as 200 knots or 300 knots plus. Also, he didn't give you a specific speed to fly I have to agree with you especially since you were pulled off the STAR.
However in general the SLP is x distance from some VOR/airport/whatever so I'd say at the very least be at speed by then. Safe skies buddy!