Whether the parties submitted anything in electronic form would not have any bearing as to whether there was an "active" docket link. A docket clerk at the court would just create an entry in CM/ECF, and then scan the submitted paper in, thereby creating the same exact entry as far as PACER is concerned as if it was electronically filed.
I obtained all the filings in the Scooter Libby case - at least all those that were made available of PACER (argument in the Circuit Court was not, minute entries and transcripts in the District Court were not), many of which were "scanned in."
Pure speculation on my part that the ED of PA has lazy clerks. If it takes one more step to get the document on line, they don't.