This has been a hot topic of discussion for a long time. The J publications only states: "A more accurate fluid level indication can be obtained by allowing SUFFICIENT TIME for as much entrapped air as possible to escape prior to checking fluid level" which is very open to interpretation. I have heard accounts that when an aircraft required both struts serviced on one side, the servicing was performed by a fairly inexperienced crew and as they did not leave enough time for all the air bubbles to escape, when they charged the strut and dropped it off jacks it seemed fine however possibly due to a dry, sticking strut (didn't lubricate chrome part of strut during servicing,) on landing, both struts bottomed out due to excess of gas in the strut and damn near tipped a wing. This probably could have been avoided had the crew tapped the strut with a mallet after servicing.