What he says is unreliable; don't take it too seriously.
Tips
usage
Almost always used with 没: 没准儿 (uncertain, unreliable, maybe). Very colloquial Beijing dialect. 没准儿 can also mean 'perhaps/maybe': 他没准儿已经走了 (He may have already left).
register
Erhua (儿化) form typical of northern Mandarin, especially Beijing speech. The base form 准 means 'standard/accurate.'
