Read it again. Cornelius received the Holy Spirit before being baptized. All others received the Holy Spirit after being baptized or later with the laying on of hands.
Again, something different is happening. Look at what Peter later says...
ACTS 15
5 But there rose up certain of the sect of the Pharisees which believed, saying, That it was needful to circumcise them, and to command them to keep the law of Moses.
6 And the apostles and elders came together for to consider of this matter.
7 And when there had been much disputing, Peter rose up, and said unto them, Men and brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe.
8 And God, which knoweth the hearts, bare them witness, GIVING THEM THE HOLY GHOST, even as he did unto us;
9 And put no difference between us and them, purifying their hearts by faith.
10 Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear?
11 But we believe that through the grace of the Lord Jesus Christ WE SHALL BE SAVED, EVEN AS THEY.
Did Peter say that people would now be saved by GRACE like Cornelius? Sure did!