Hello XXXXXXX, you didn't hurt anything. Having a half quart of 10w30 mixed with 4.5-5 qts of 5w20 will not give you any problems. It will mix and thin out in the crankcase. Don't let it bother you. There are many non-blondes that have done the same thing so don't feel bad, no harm done.
Your JA Expert,
Ivan
ASE Certified Master Technician
ASE Master Tech w/ 19 years in the field. Self employed for 9 years. Member of AUTOLAB radio show.